They should get the best metrics out of update server communications anyhow, 30% or more users getting update downloads than having AI enabled should be obvious.
There'll be so much noise in that signal it'll be almost useless. You can't differentiate it from anything else. For all anyone knows it happened because the word Firefox was in the top story on hacker news
Here's my thinking: There's 100 users getting updates. There's 40 users sending telemetry with AI enabled There's 10 users sending telemetry with AI disabled
So we have 50 people not sending telemetry and using or not using AI. If we assume more likely but not overwhelmingly more it's 30 people.
So we end up with 40+20 with AI, and 10+30 without?
When you disable telemetry you are declaring you don't want to be tracked.
Still, AI services cost money they probably want to check usage since money talks.