IMO its because the demand for ever growing growth (not only must we grow on last year (growth up 5%), but our growth must be faster (growth trajectory up 5%)) is running headlong into a shrinking economy. Anonymous users have always represented the best potential growth since they already use the service, so convincing them to convert should be easier than convincing someone who has never heard of the product. Ergo,…
Now they are facing existential risk and they don't really have a choice, if pissing users off is the way they can punt on revenue then they are going to do it.
Ultimately I think it signals that a lot of these companies (not ones that have been bought by FAANG) are functionally insolvent and are in a slow death spiral.
I bet many of them will start looking to illegally broker user data as that reality gets closer.