July is the real indicator with API being turned off on June 30th. I don't think the protests themselves had a big enough drop off, but I have to assume a lot of folks have either left or use only desktop currently once that happened.
The API hasn't been "turned off", there is still a free tier (very limited) and a paid tier (very expensive), plus some 3rd party apps have been spared and are still working.
To be honest, it looks like their attempt at monetizing the API wasn't even turned on yet. They just blocked certain API keys from being able to use oauth. Which is what broke RedReader despite it supposed to be spared for blind people.
All third party apps are still working, you just can't log in. Apps who decided to charge a monthly fee still have no pricing from reddit and are still operating for free until reddit figures out wtf they are doing, or at least that's what I've gathered based on the announcements from those apps.
NSFW content was supposed to be removed from the API yesterday but still nothing 🤷♀️