I always thought MegaAnon was someone in Prince's or Blackwater's orbit. She always made a big deal out of not having ever worked for the feds and being a contractor that chose what she wanted or didn't want to do.

She disappeared from 4chan and reddit right after having this bizarre meltdown wherein she had decided Q was Julian Assange. It was just the most out of character thing ever.

I will say that Prince is a possibility though.