[**Spoilers for Secret Avengers, Vol. 2: Eyes Of The Dragon (2012) and Avengers World (2014-2015)!
*Note: This is strictly an opinion piece. There has been no news of the character Shang-Chi joining any show or movie in the Marvel Cinematic Universe.]
Shang-Chi is a somewhat obscure Marvel Comics Character that debuted during the 1970s martial arts craze (Specifically 1971 in Special Marvel Edition #15). He would go on to guest-star in several books including the 2017 event Secret Empire, and occasionally starred in his own titles such as Master Of Kung Fu (1974-1983). Despite all of his appearances, he has never really exhibited a defined personality.
So, headlining a show or movie would be tricky if the cast and crew try to remain faithful to the comics. In other words, we could see another version of Marvel’s Iron Fist (2017) or Twentieth Century Fox’s Elektra (2005).
Also troubling is the potential for racist handling. Originally Shang-Chi was the son of the immortal “Yellow Peril” villain Dr. Fu Manchu. This was retroactively changed in Secret Avengers, Vol. 2: Eyes Of The Dragon (2012) due to rights issues, and probably also the fact “Yellow Peril” villains like Dr. Fu Manchu are examples of racist presentations in comics. However, he is still the son of a villain and an Asian character that only knows martial arts, so there may still be talk of stereotyping. Yes, he gained the power to create duplicates of himself in Avengers World (2014-2015), but that would likely be a concept to explore after a first movie or television series.
Not to mention there could be other problems. Such as any efforts by Marvel to market him being countered by racist media sources. And this is not even considering the ill will that Marvel’s Iron Fist (2017) produced due the poor choreography on a martial arts-centric show. And let’s not forget that one of Shang-Chi’s regular supporting cast, Black Jack Tarr, refers to Shang-Chi by a racist nickname. So promoting both a show, movie, or guest appearances would be trickier due to not being able to draw much on the old comics for these reasons.
In conclusion, until Shang-Chi gets more substantial character development, and the troubling aspects mentioned above are addressed, it would be better for the Marvel Cinematic Universe to wait on a possible appearance for the character.