Literally just install the app & give them credentials (or sometimes make an account with them), no asking or selling, just presenting the new fact of life.
(Tho I still preach about foss and how privacy isn't just for them, but for moral reasons of not giving megacorps more power because they never use it for good)

"For you nothing is actually different, just the apps icon is different now."

I also keep group names & profile pics the same.

I mean, from noob user pov what even is the difference?