He doesn't have much more to say on Twitter. Must keep an eye on it to see how it goes.
It sounds like FB suspended the hijacked account, he's cleared out of FB and considers the matter closed.
So Myst VR is available on GOG now (waves vaguely at previous posts in the thread) but not at the £2 or thereabouts that I envisaged. It's actually the same price as Steam. Give it a few months though.