It has been revealed that Square Enix has registered two titles connected to the Tomb Raider IP.
The first one is simply riseofthetombraider.com, and the second one carries the name laracroftandthetempleofosiris.com.
Neither of them sounds like a true sequel to last year's Tomb Raider, instead they could possibly be related to Lara Croft: Guardian of Light.
A reasonable assumption would be that we'll know more shortly, with E3 set to begin, and this is something that Nintendo Force editor Emily Rogers semi-confirms with this topical Tweet:
I think Guardian of Light fans will be happy in near future. That's all I'm going to say. Not a mobile-only project.