the problem occurs when most of the content comes from Meta (they will likely have the vast majority of Fediverse users). especially if major communities exist on their instance. when meta decides to no longer support fedi integration, those in the fedi are forced to decide between staying with their communities by ditching the fedi and moving to threads or having many of their communities ripped away.
meta will do this at some point as a play to draw users to them, but we can decide if we want to be affected when that comes to pass.