DisableFetchTracking default with 2.8.x lead to significant Azure consumption

[coreyroth]

I know it was in the release notes and we didn't fully realize the scope of the change. However, when you changed disableFetchTracking default to false instead of true, it lead to more than a 10x increase in logging on one of my instances. I had Ajax tracking disabled explicitly already but not this one since it was previously defaulted to false. It went a while before anyone noticed, but we're looking at a cost impact of more than $10k per month. I haven't finished full analysis but this affects us on 100+ customers of varying size. I admit we should have caught it in testing, but this change hurt.

[MSNev]

related #1808