Newly released features mean new bugs right? I dorked changelogs/development progress tracking pages for >200 bug bounty programs (excluding VDPs), parsed them and created a list containing the most informative and constantly updating changelogs. If you have something to add, feel free to drop a pull request - I'll add a changelog if it's interesting enough and the last changes were recent.

Public:

Twitter: https://twitter.com/i/release_notes

Hey: https://www.hey.com/new/

Slack: https://slack.com/intl/en-gb/help/articles/115004846068-Slack-updates-and-changes

Hackerone: https://docs.hackerone.com/changelog/

Bugcrowd: https://docs.bugcrowd.com/changelog/

Tinder: https://www.tinderpressroom.com/news

Stripe: https://stripe.com/blog/changelog

Reddit: https://www.reddit.com/r/changelog/

WHMCS: https://docs.whmcs.com/Changelogs

Mattermost: https://docs.mattermost.com/install/self-managed-changelog.html

Lark Technologies: https://www.larksuite.com/hc/en-US/articles/360046836333

Yoti: https://developers.yoti.com/v6.0/stay-updated/ageverification-release

Netlify: https://www.netlify.com/tags/changelog/

Basecamp: https://basecamp.com/new

Figma: https://releases.figma.com/

Invision: https://invisioncommunity.com/release-notes/

PingOne: https://docs.pingidentity.com/bundle/pingone/page/iqi1564020491724.html

Nordvpn: https://nordvpn.com/ru/blog/nordvpn-windows-release-notes/

Coda: https://coda.io/updates

Tube8: https://blog.tube8.com/category/announcements/

Matomo: https://matomo.org/changelog/

Chaturbate: https://chaturbate.com/apps/docs/changelog.html

Bitmex: https://www.bitmex.com/app/apiChangelog

Vanilla: https://success.vanillaforums.com/kb/articles/126-release-notes-overview

Youporn: https://blog.youporn.com/category/youporn-announcements/release-notes/

Discourse: https://meta.discourse.org/c/releases/30

Quora: https://productupdates.quora.com/

Dashlane: https://support.dashlane.com/hc/en-us/articles/360014017920-Admin-Console-updates

Zendesk: https://support.zendesk.com/hc/en-us/sections/360004061994-Release-Notes

Shopify: https://changelog.shopify.com/

Imgur: https://blog.imgur.com/category/updates/

Greenhouse: https://support.greenhouse.io/hc/en-us/categories/360000322491-What-s-new-

Canva: https://www.canva.com/whats-new/

Soundcloud: https://github.com/soundcloud/api/releases

MyEtherWallet: https://github.com/MyEtherWallet/MyEtherWallet/blob/main/CHANGELOG.md

Elastic: https://www.elastic.co/guide/en/elasticsearch/reference/current/es-release-notes.html

Brave: https://brave.com/latest/

Wordpress: https://codex.wordpress.org/WordPress_Versions

Airtable: https://www.airtable.com/whatsnew

Django: https://docs.djangoproject.com/en/3.2/releases/

Epic Games: https://trello.com/b/GXLc34hk/epic-games-store-roadmap

1password: https://releases.1password.com/windows/early-access/

Okta: https://developer.okta.com/docs/release-notes/

Jira: https://confluence.atlassian.com/jirasoftware/jira-software-release-notes-776821069.html

Intercom: https://www.intercom.com/changes/en

You need a budget: https://www.youneedabudget.com/release-notes/

Lastpass: https://lastpass.com/upgrade.php?fromwebsite=1&releasenotes=1

DigitalOcean: https://docs.digitalocean.com/release-notes/

Discord: https://discord.com/developers/docs/change-log

Instacart: https://docs.instacart.com/connect/api/fulfillment/changelog/

OpenSea: https://docs.opensea.io/changelog

Krisp: https://whatsnew.krisp.ai/

Exodus: https://www.exodus.com/releases/

Aiven: https://aiven.io/changelog

Acronis: https://www.acronis.com/en-sg/support/updates/changes.html?p=42226

Facebook:

• Graph: https://developers.facebook.com/docs/graph-api/changelog/
• Messenger: https://developers.facebook.com/docs/messenger-platform/changelog
• IG API: https://developers.facebook.com/docs/instagram-api/changelog
• Whatsapp for business: https://developers.facebook.com/docs/whatsapp/business-platform/changelog
• Quest: https://store.facebook.com/help/quest/articles/whats-new/release-notes/
• Oculus browser: https://developer.oculus.com/documentation/web/browser-release-notes/

Google:

• Chrome: https://chromereleases.googleblog.com/
• Chrome enterprise: https://support.google.com/chrome/a/answer/7679408?hl=en
• Cloud: https://cloud.google.com/release-notes
• Android: https://developer.android.com/about/versions/12/release-notes
• YT: https://support.google.com/youtube/answer/9730487?hl=en
• Waze: https://developers.google.com/waze/wam-api/resources/change-log
• Google earth: https://developers.google.com/earth-engine/changelog?hl=en
• My business: https://developers.google.com/my-business/content/change-log?hl=en
• Recaptcha: https://developers.google.com/recaptcha/docs/changelog?hl=en

Apple:

• General updates: https://developer.apple.com/news/releases/?id=12072021h
• MacOS: https://developer.apple.com/documentation/macos-release-notes
• IOS/IPADOS: https://developer.apple.com/documentation/ios-ipados-release-notes
• Safari preview: https://developer.apple.com/safari/technology-preview/release-notes/
• Safari: https://developer.apple.com/documentation/safari-release-notes

Microsoft:

• Office: https://docs.microsoft.com/en-us/officeupdates/
• Office MacOS: https://docs.microsoft.com/en-us/officeupdates/release-notes-office-for-mac
• Graph: https://developer.microsoft.com/en-us/graph/changelog/
• Windows 10: https://support.microsoft.com/en-us/topic/windows-10-update-history-53c270dc-954f-41f7-7ced-488578904dfe
• Edge: https://docs.microsoft.com/en-us/deployedge/microsoft-edge-relnote-stable-channel
• Azure: https://docs.microsoft.com/en-us/azure/active-directory/fundamentals/whats-new
• Exchange server: https://techcommunity.microsoft.com/t5/forums/searchpage/tab/message?q=updates%20exchange%20server&noSynonym=false&collapse_discussion=true
• Skype: https://support.skype.com/en/faq/fa34778/what-s-new-in-skype-for-windows-mac-linux-and-web
• Linkedin: https://www.linkedin.com/help/talent-hub/answer/a147710
• Linkedin Marketing API: https://docs.microsoft.com/en-us/linkedin/marketing/integrations/recent-changes
• Github: https://github.blog/changelog/

Roblox: https://devforum.roblox.com/c/updates/release-notes/62

Rockstar launcher: https://support.rockstargames.com/search?query=Rockstar%20Games%20Launcher%20Release%20Notes

Firefox:

• Desktop: https://www.mozilla.org/en-US/firefox/100.0.1/releasenotes/
• Android: https://www.mozilla.org/firefox/android/notes

Kubernetes: https://kubernetes.io/releases/

Splunk Enterprise: https://docs.splunk.com/Documentation/Splunk/8.2.6/ReleaseNotes/MeetSplunk

Seek: https://developer.seek.com/introduction/release-notes

Expressvpn: https://www.expressvpn.com/support/release-notes/

Imperva: https://docs.imperva.com/bundle/articles/page/73179.htm

Cloudflare: https://www.cloudflare.com/whats-new/

AEX: https://www.aex.com/page/doc/en/update/update.html