Indeed, the terms "biologically male" and "biologically female" have been described by activists who are not at all aligned with Trump as "trans-phobic" and a "TERF dogwhistle" so it's strange to see these two groups suddenly agreeing with each other over something.
It's a rhetorical wrestling match, not an agreement. Moreover, the reality of the majority of the larger movement doesn't always align with the loudest voices in the room, especially when it comes down to semantics. Meanwhile any search for truth in the form of science suffers.