I don't think they've actually done it yet. Probably waiting to see how much of a backlash there is before changing their minds (and capturing a bunch of new subscribers in the process).
Ah ok, that DC Rainman guy had posted screenshots so I thought it was live. When I look at app updates there’s one from a day ago to v150.0.1 for Strava and the description says stuff about focusing on subscribing users.
I don't think they've actually done it yet. Probably waiting to see how much of a backlash there is before changing their minds (and capturing a bunch of new subscribers in the process).