Sorry I’ll let someone more knowledgeable answer about metadata, but signal does allow you to set a username and hide your phone number (so people add you with username instead if f number)

I’ve honestly found signal better than matrix.

Matrix is just not there yet in terms of features UI etc and is less private than signal because it collects way more metadata and stuff. I know the idea of federation is cool, but Signal works better for the privacy aspect.

Nah they used a leeching client. No upload at all.