Missing mention_roles in message snapshots

[MinnDevelopment]

Description

The message snapshots seem to sometimes not include the required mention_roles property, if the message is forwarded from another guild.

  "message_snapshots": [
    {
      "message": {
        "components": [],
        "attachments": [],
        "mentions": [],
        "flags": 0,
        "type": 0,
        "embeds": [],
        "edited_timestamp": null,
        "content": "<@&1291689786570047529>",
        "timestamp": "2024-10-04T09:20:03.181000+00:00"
      }
    }
  ],

This property is required according to the spec in MinimalContentMessageResponse.

Steps to Reproduce

1. Create a new guild with one role
2. Mention the role
3. Forward the message to another server the bot has access to

Expected Behavior

The required properties should be present.

Current Behavior

Missing mention_roles

Screenshots/Videos

No response

Client and System Information

Gateway v10

[MinnDevelopment]

For more context, this is only observed on gateway message create events. For GET requests the mention_roles list is present and even includes the IDs of the mentioned roles.