Not sure why people are saying that ROTTR sold terribly, it likely match or even surpassed Tomb Raider Definitive Edition lifetime sales already on the Xbox One. It also be noted that first week of Tomb Raiders first week on the 360 is at 104K but the 360 installment was at 8 million. So ROTTR actually sold well even with competition like Fallout 4 releasing on the same day. The holidays will also help sales of ROTTR.
It sold ok in UK but unless SE manage to reduce delopment costs significantly for this game, profit wise the game won't be there. If I remember correctly TR 2013 ended selling around 4 million between ps3 and xb360 and even then, SE was disappointed with the sales until they released the game to current gen consoles. Also don't forget that the new game also released on xb360 as well and did around what? 10k on xb360 compare to 104k from the last game. it's obvious the success of the game depends hugely on xb1 version compare to the other game that was on multiple platform. Don't forget also that xb1 barely has install base outside US and UK so if the game sells ok in those regions, the legs will be minimal.