From the article:
Meanwhile, the blackout has affected Reddit in other important ways. There’s been a small, but growing push among some power users to federated Reddit alternatives like Lemmy and kbin. These decentralized platforms are still niche, and have many of the same challenges as Mastodon and other Twitter alternatives. Yet there seems to be growing interest from some corners of Reddit in recent weeks.
I think the key is element is that these new communities are “growing”. If they can get and maintain a critical mass of users to provide enough content and interactions to remain viable, then they can continue to develop as alternatives.