Mixed. On the positive, the fediverse is meant to be open for all, and the fact that it appeals to the corporate overlords means its demonstrated at least some degree of staying power. Further, this will bring far more people into the fediverse to interact and play with. On the negative, meta is a parasite, and most of us who are excited about the fediverse are going to gravitate to instances that defederate from Meta (and probably tumblr, too).

So on the whole? Its a neutral thing