It's a very very loose theory - I kind of noticed that they popped back up when Rosie went quiet, and I thought that might be a bit like they've got more time on their hands? and I just thought, oh that could be interesting. Their profile picture kind of gives me the feeling they're hiding in plain sight. I don't think I've seen them on this thread before.
I haven't done my tattle duties or digging deep or due diligence, so I could be very very wrong.