I'd bet at launch the number of Xbox one X titles at native 4K will heavily outweigh the number of 4Kc. Simply because I doubt the pubs of many of those 30+ titles confirmed for a post 4K patch are willing to invest in some CB solution for free. But I also think it will remain that way for awhile.
CB benefits are obvious but how much effort (cost to pub) does it take to implement and make performant?
I ask because while the PS4 Pro was designed with CB in mind and while it seems some aren't all that positive about associating the Pro with native 4K. There are plenty of native 4K titles on the Pro and far more than CB titles. CB seems to be limited to just high budget AAA games.
Ubisoft obviously have their version of the tech and have been using it since Rainbow Six Siege. EA have it in the Frostbite Engine (I had to look this up after Anthem was revealed to be using checkerboarding, so I guess SWBF2 is likely to be CB after all!)). So, yeah, AAA is probably pretty well covered as I doubt that those are the only multiplatform publishers who will integrate that support into their engine. It isn't just good for PS4 Pro, but will help boost marginal (for 4K rendering) PC configs to 4K as well. But, I also see some studios choosing to use Sony's ready-made solution for PS4 Pro and then just running native on One X because it's easier.
Honestly, I think the "True 4K" stuff is unfortunate, but I see why they are doing it. If they can make that matter to people, it's another selling point for their console. But, it's going to be fodder for so much ignorant shit from fanboys. And it really doesn't matter. I'd rather they just continued to bang the drum on hardware specs.