This is just a theory I came up with months ago but forgot to post it.
People are often saying how the MCU is setting up for the debut of the Young Avengers, of which there is founding member Iron Lad, a younger version of Kang the Conqueror.
With people wondering who would become Iron Man’s legacy, well, why not his daughter. I believe in the MCU, we could get a female version of Iron Lad (Iron Lass) and Kang the Conqueror (Conqueress) to be the new big bad of the MCU.
Katherine Langford could play Iron Lass, a future version of Morgan who’s trying to stop her future version, Kang, from conquering different time periods in pursuit of gathering an army so big it can defeat Thanos in 2023 without Tony’s sacrifice. This could work with the MCU’s established time travel rules, with Kang’s time-hopping not really affecting the main MCU timeline.
To me , I just think it’s an interesting way to not missuse Langford’s casting and create a threatening big bad (bonus: it’s female this time around).
P.S. I do think it might be a shame to not make Kang a distant relative of Reed Richards and Sue Storm, though, as introducing him/her into the MCU with ties to the Fantastic Four would be a good way to bring them into the cinematic limelight.