New concept art from Shang-Chi and The Legend of The Ten Rings reveals Deadpool was in the film. During the cage fight Ryan Reynolds’ Deadpool fight with Proxima Midnight, which is cut from the film. Proxima Midnight was one of Thanos’ children. Check out the concept art below.
Concept artist Andrew Kim (via Murphy’s Multiverse) shared recent art for Shang-Chi and the Legend of the Ten Rings that are all based around Xialing’s Golden Daggers Club. The final cut was added with two biggies MCU cameos Wong (Benedict Wong) and Abomination (Tim Roth) in the cage fight.
Still, there is no idea about recent Shang-Chi concept art, whether it is Marvel Studios suggestion or Kim do it for fun. Proxima Midnight died in Avengers: Infinity War (and again in Avengers: Endgame).
Proxima Midnight is a member of Thanos’ Black Order and one of the best combatants of the Mad Titan’s army. So, not only is she loyal to her master the Mad Titan, but she is also allied with the other original, ruthless members of the group: Corvus Glaive (her husband), Supergiant, Ebony Maw, and Black Dwarf.