I can’t know Meta’s internal strategy for sure, but I’d speculate that they see Twitter as the primary competitor to Threads by a significant margin.

Fediverse integration, introducing fediverse concepts to a large number of people, seems more likely part of one-upping Twitter rather than an attempt to kill the fediverse.

Meta has (tried to purchase or shut down its competitors on multiple occasions)

Google (gmail) and Microsoft (hotmail/outlook) are both infamous for anticompetitive behaviour.