On SteamDB, it actually shows up with Linux, Mac and Windows all together in the "oslist". This is by no means confirmation, as we've seen this happen before with a Linux version never releasing, but it's still a good sign.
As a huge Theme Hospital fan, a proper spritual successor sounds pretty awesome. The developer, Two Point Studios, actually has people from Bullfrog, Muckyfoot and Lionhead so they certainly know their stuff.
We have reached out to the developer for confirmation, no reply as of yet. Will keep you posted if we find out any more.