Do you have reason to believe any of that is happening?
You could de-anonymize many users with those
Bruh your Facebook username is literally my first and last name. Same goes for most people on most platforms. I don’t particularly care about anonymity.
Any fediverse apps could also get access to contacts or other locally-stored info on your phone.
I’ve never used a Fediverse app that asked for any of that. They have no use for it.
“But I wouldn’t use that app.” Well then you wouldn’t be someone using Facebook either.
You don’t seem to understand the myriad of data that Facebook collects unnecessarily and without user consent. Do a search for Facebook Pixels. They were just caught decrypting traffic from SnapChat. Most Fediverse servers are far too small to even bother with collecting and selling that sort of data.