In November last year, Microsoft confirmed that it had reached the extent of its capabilities and would no longer add more original Xbox and Xbox 360 games to its backwards compatibility library. But, it appears that things have changed with the tech giant's acquisition of Activision Blizzard. Now that Microsoft owns more IPs than it could possibly know what to do with, it plans to revisit its decommissioned initiative for one last try.
Nick "Shpeshal" Baker claimed on a recent XboxEra podcast episode that he holds a list of older Activision Blizzard games that will become backwards compatible for the Xbox One and the Xbox Series S/X. Unfortunately, Shpeshal declined to reveal anything on his list. But, he did clarify that fans shouldn't expect anything with licensing issues like Deadpool and other games published by Activision that you can no longer buy.
Even if we rule out licensed properties from Hasbro and Marvel, Activision Blizzard's coffers are deep enough that the list could literally go on forever.