Ml is run by the creators of Lemmy, and hexbear is well… Not. Hexbear made their own fork of lemmy a long time ago and only in the past year or so have they been actually able to federate at all. I don’t see the creators of Lemmy going through all that effort to hide their identities if they were actually running hexbear behind the scenes
Hexbear is where the chapotraphouse users largely have landed assuming they followed the direct line of succession. There probably is some contingent in Lemmy.ml, but not because it was the successor