I could see them releasing a Legacy of Kain after they're done with Tomb Raider 3. It'd be like what Naughty Dog did with their development cycle.
Uncharted 1 > Uncharted 2 > Uncharted 3 > The Last of Us > Uncharted 4
Tomb Raider > Rise of the Tomb Raider > Tomb Raider 3 > Legacy of Kain > Tomb Raider 4
Would actually be kinda dope because it would be something new and it would give Tomb Raider a break, which it'll probably need after Tomb Raider 3. It would let Crystal Dynamics do something different for the first time in like 10 years, and also allow them make really fresh Tomb Raider 4.