There's not much to it, really. I don't know anything about the person who is taking over Steemit.chat, and just browsing through their profile and their activities didn't inspire any confidence as to being someone I'd trust with my information and my communications. It'll take them some time to build my trust, at which point I'll rejoin Steemit.chat. So this is more of a guilty till proven innocent kind of case. Paranoid, perhaps, but I'll play it safe when the question of my privacy is at hand.