It certainly seemed for all intents and purposes if you were a member of _____ group (wider than the company) you had the vpn on your device, and it was filtering content. I've found other reports in other countries of that happening with the same group.
So it's not corporate content filtering, it's personal content filtering and our app got caught up in it (and approved).
It certainly made my skin crawl for anyone in that religion. That means the central filtering service could be reading messages. Not sure if they're that sophisticated but certainly they didn't want people to see random images/videos.
You could imagine a standard for a network to signal to a client that it does not allow certain privacy features like ECH, and then clients can accept that or not. Instead I expect browsers will eventually mandate ECH, so people will have to MITM instead.
It also sounds like their issue was at the ISP provider level, as well, which takes the business out of the loop of being the data controller/owner (of the collected data) at that point.
Note: I'm not saying that your comment doesn't have merit, I just don't think that the points that you made apply - specifically - in this case?
So, member of the church? you get this VPN on your phone, (not sure whether phone was supplied by the church, but certainly this VPN was on it) VPN is effectively content filtering and blocking content.
I had our app whitelisted by that central company (literally raised a ticket with them, next day magically fixed).