"lost" is incredibly misleading, as there's no evidence they weren't paid to hand the handles over.
The odds of X forcefully handing a handle over from a user to Meta for an AI product seem lower to me than them being paid for it, but that's not based on anything either.
Using "lost" in a headline is therefore misleading, as it implies a lack of consent where there is no actual knowledge that is the case.
I don't think so, because if it was involuntary from Muse the band, surely they would post something about it. They would get a ton of publicity and goodwill for shit talking Meta, and the fact that they aren't makes it much more likely that they were paid for it.