@pixelfed huh, looks like illegal anti-competitive activity to me, seems that they are attempting to "hinder other businesses from entering the market", and acting to "maintain or acquire a dominant position by excluding competitors or preventing new entry". Maybe qualifies as "refusal to deal", though not sure.

ftc.gov/enforcement/anticompet

Related, see how it went when Twitter did similar: commondreams.org/news/2022/12/