They don't specifically mention PC-only, but I guess up until now the consoles haven't really been the home for Free To Play games.
I'm going by what one of the devs said in their forum
*Reign of Thunder is an all new, unique IP by Day 1 and not affiliated with any previous license.
*We will regularly release new Mechs and equipment and want your thoughts on future releases.
*Thunder is currently 16 players on the PC.
*We do have plans to allow players and clans to host custom matches.
*There will be support for custom skins and decals along with all the standards, weapons, components, etc.
*Yes, there will! Sign up on the front page of the Thunder site or email me at [email protected]
I know he says currently, so that could change, but for now it's really a PC topic.