I voted Taris because it seems the most likely. We already saw a reference to it being rebuilt in a screenshot, it was in aurebesh on a display.
I'd rule out Corellia, Dantooine, Kashyyyk, Tatooine, and maybe Hoth since TOR so far has been making sure not to recycle planets used in SWG. We can rule out a few for lore reasons too. Tython fills the niche of Jedi Temple planet, so no need for Dantooine. Hoth is a cold hellhole thats only relevance was the Rebels picking a base, which they did because it's never had anything happen there. Anchorhead is swallowed up by the sands regularly, leaving no habitable settlements on Tatooine; I think Anchorhead's covered up currently. Dagobah is likewise a nothing world that made it perfect for Yoda to hide on; I can't imagine any sort of content there. I don't know much about Kashyyyk and Corellia in this era, have they been in the Threat of Peace comics?
"Sir,we are beginning our search for these rumored 'underwater villages'.They will not stay hidden for long". -Battle Droid Commander OOM-9!