Michi has pride andimplied Niji would not have let her post about it as Mika rare Niji Wscratch that Niji W rescinded
Edit: it's a bi flag
I think if it was Niji that stopped her talking about it, it must have been an ID specific thing. Since Uki is the second gayest man alive behind Proctor and everyone else is relatively open about flying some flag (overwhelmingly Bi).
Even in JP you had Gundou talking about looking around in a lesbian bar, struggling to find people she's never seen without pants on, and Ryushen who talked about the Japan exclusive term "X-Gender" and other LGBT topics before, including being "Gender: undisclosed" themselves.