It was my post you quoted (aware I'm not the only person on this thread voicing this issue, though):
"the seemingly very racialised banning of a Black woman"
You're right that none of us yet know why Aja and Lippy were banned. However, it's not at all ridiculous to acknowledge the racist overtones in MH's blog relating to this aspect (Milli's self-reported anxiety that Aja was there to attack her, rather than simply because it's a massive feminist conference; and the FiLiA volunteer she reports as helpfully pointing out Aja to her, as if she's some sort of threat to be aware of) - which actually constitutes a massive proportion of what is currently known about this ban!
And, of course, none of us can really prove that MH being (or claiming to be) frightened of Aja, and a FiLiA volunteer apparently humouring that, had anything to do with race. Maybe it did, maybe it didn't. But there is a rich fucking history of White women weaponising their fears of Black people (men and women), and of Black women being perceived as aggressive, excessively angry, difficult. So until I hear otherwise, I'll continue to recognise that this unexplained banning, which nobody seems to have any explanation for, and which FiLiA has yet to comment on, seems to have taken place in a racialised context.