Apparently, Deadpool could have had a cameo in Shang-Chi

For example, how exactly is Proxima Midnight still alive? Thanos' adoptive daughter already died during the events of 2018's Avengers: Infinity and 2019's Avengers: Endgame, so it wouldn't make sense for her to appear again in Shang-Chi. Of course, her appearance in the Shang-Chi concept art suggests that this is something that Kim did for fun and perhaps attempted to pitch to Marvel Studios but failed. This also means that we'll never know if Ryan Reynolds' Deadpool was ever meant to appear in Shang-Chi at all.

According to Reynolds last August, Deadpool 3 will start filming this year. Then, a few weeks ago, the Deadpool actor teased that he'll have more to say about the upcoming Deadpool threequel soon, which could mean that production on the movie is starting soon. But, even if it makes the most sense for Deadpool to barge into the MCU in his movie, we wouldn't put it past Marvel Studios to have him do a cameo or two in an upcoming film.

Case in point, some people believe that Deadpool will appear in Doctor Strange in the Multiverse of Madness. Although unlikely, it's not impossible either - a variant of Patrick Stewart's Charles Xavier is all but confirmed to appear in the Doctor Strange sequel already. As a multiversal affair, Doctor Strange 2 could help explain why Deadpool is in the MCU in the first place.

Ultimately, fans should not worry too much about Deadpool's MCU debut - this is all a matter of when and not if.