The post on Mastodon has a screenshot of the post edit history:

And a copy-pasted response from a moderator (the most relevant bit):

So in my opinion, if your intention was to show political support for diversity, you should avoid using this flag. This will allow us to refuse the use of a flag for instance saying ‘non-queer’, If we allow your flag, then we have to admit also other similar political flags, both supporting and opposing diversity.