I think my unwillingness to accept the party explanation is down to 2 factors:
If the problem was bullying, or specific social media posts, or anything reasonable, that should be a perfect defense against transphobia. Unless the posts reveal protected information, there is no reason to hide behind process. The media is already reporting on it, so make this about the content not the candidate.
Unless he’s had some dramatic change of heart, Kai is clearly a transphobe or sympathizer at best. If he’s running the suspension process, that’s one great reason to be skeptical of anything he says.
I am willing to believe the candidate was difficult but edge cases are where we decide who we are as a society.