This is bang on, but I came to this same thought through a slightly different route (a thought I had reading @rjelevi.bsky.social's "When we collide"): Cis-normativity entails a narrow, monomaniacal view of how a body is supposed to be/look/work, the foundation of ableism.
As I've said since the beginning of this nightmare, transphobia is inextricable from ableism. They are the same mechanism producing the same results for the same reason. Any disabled people throwing their lot in with transphobes are sowing the seeds of their own destruction.