Fractal calls them Historical rooms and they are rooms that I left on other apps.
I thought that when you leave a room on e.g. Element it’ll send a deletion request to the server and then to other servers if applicable. But I can see all historical rooms and the data is still there. It even shows when I left the room.
How scary is that?
Have you checked on Element to see if the rooms appear there? Generally, when you leave a room on Matrix the homeserver you’re on still holds a copy of that room that is cached until you “Forget” the room (and on the backend, its completely removed when all users on the homeserver have left the room AFAIK).
Matrix does not delete your messages from the room whenever you leave a room though. What I don’t know is what happens when your account is deleted, however.
They do not appear in Element. I’ve never seen “historical” rooms there.
Sounds like there’s a reason why it’s nowhere called “delete room”