@johnhang123
nah, keep in mind when they have white people play asain characters for adaptations (this is something only the west gives a shit about, the japanese fans just want to see the movie doen live action) its a star power draw, try and get some normies into the seats.
opm's world allows them to race and gender swap anyone because of how weird everything is, its a niche movie that also means few outside of anime will care, and japanese will just be happy its a movie. if there was one part of the story that could be turned into a movie right now, it would be the monster association arc, but god knows that be the backdrop, they will instead make an 'original' story about the evils of white men and how its the strange people who are heros to rise up.
oh, saitama could be male if they make him gay, but I would still be betting on a race swap. the only character who wont be swapped at all will be Puri-Puri Prisoner, they will make damn sure to keep him as close to original as possible.
hell, they may set it before the opm story starts so they can justify saitama not being able to one punch, and if they have any semblance of timing they would end it with the first serious punch, but that's giveing holywood credit