This vibes anecdotally with my local chapter. In the face of overwhelming membership solidarity with Palestinian liberation, the social imperialist reactionaries are purging themselves.
It sounds like it’s moving left, though it also sounds like this has only been possible due to a mass drop in membership following the failure of the Bernie campaigns. Marxist Unity Group seems like their worth checking out as an internal bloc to the DSA and where it could go
Funnily enough, the 3 he listed (Red Star, MUG, and Commie Caucus) are the 3 I’d most recommend people check out. Unless you have a strong preference for one of them I’d just join whichever is most active in your area.