What would be his motive for saying revenue would be $10B less than previous trends would predict? They posted record revenue again in 2021, so it doesn't look like he's trying to cast a scapegoat for stagnant revenue.
According to what I read (not first hand, of course), he said that 10bn because of Apple's decision. That's a different thing than just saying 10bn, and to pressure Apple to let loose on privacy seems motivation enough to me.