This is about as close as an "official word" as we're gonna get until it's probably released:
I've only known about Overloud since 2011 or so, but they seem to never explicitly pre-market any of their products, and only do any visible marketing until after a product's shipped. One of their recent picture uploads on their FB page also shows one of the devs running a Rocktron Cottonmouth Fuzz through an oscilloscope with "work in progress in guitar fx" in the description. So TH3 is definitely at least still in development as of August, but I'm not too confident in the teaser cover picture being an outright, sneaky declaration that it'll be out really soon. Hopefully it'll at least be out by next year, and it'll have some more boutique pedals (with some licensed replications,) and MoReVox reverbs built in since that seems to be the way their development cycles have been going recently.
Edit: I haven't posted enough for links to appear it seems hahaha. I meant to link a post to the page from June 29th, so now I just look dumb.