Rooms in Matrix are hosted on every server who participates in them - just because the alias is #somewhere:matrix.org doesn’t mean that if matrix.org goes down

Rooms in Matrix are hosted on every server who participates in them - just because the alias is #somewhere:matrix.org doesn’t mean that if matrix.org goes down the room disappears. However, user accounts aren’t portable yet, sadly. So the problem is more that if matrix.org disappeared then it would impact the user accounts homed on it.