I have a request to any mods/admins/instance owners reading this:
You might get some mileage by putting sticky posts up, ideally in as many communities as possible, warning users about using Meta's app. Make it so every time a Meta user comes and checks us out, they're reminded, over and over, that Meta is spying on them. Repetition gets the message into people's brains!
"Did you know Meta's app watches and times your doomscrolling, and phones home to Meta to tell them which stories caught your eye? It records everything you type, even what you go back and delete, and sends that home to Big Brother. Consider using a spyware-free app, here's where you can get them..."
I don't know if there's a way to put up that warning, but only for people using Meta's app or coming from a Meta instance. Probably not, unless the developers put that in.
Yeah, for people using other clients or just on the web page, it's preaching to the choir, but if there's going to be a huge influx of Meta users, I think the newbies need some friendly education.