Sorry for the thread necro, but what is the movement on a linux release? I love Torchlight 1 and 2 because they are great games AND are linux friendly.
It won't directly answer your question about a linux release but it will assist you on what platforms they are shipping for. The platforms that they have said are the Windows (there's a steam page) and PS4 platforms at its current state. You'll have to keep an eye out if there are anymore details.
Just PC and PS4 for initial release. We're a small studio with our own tech and this is the first time we're doing multiple platforms at launch. Trying to keep things (relatively) limited in scope!