I think if you made KOTOR, then you don't worry about the reveal being a surprise, but try to get the audience to invest in the characters so that when the reveal happens it is very emotional. I never felt like the game made it a huge surprise anyway, there were so many clues. I think if they did produce a series on it then I'd support a modest rewrite to make it workable as I don't think it is in it's current form. For example, the MC dreams where the next location is every time you arrive at a new planet. But it's a limited choice of planets that are all plot relevant. I'd edit that so that while there are still dreams and visions, there is also some kind of plot reason to go there too. Tbh, I also feel like 5 planets and then the hidden planet is too much for one story to make them all relevant. I'd scrap Tatooine and Manaan as I don't feel they are particularly relevant. Korriban should also be changed a bit.
You know though what I'd really like. I'd love it if they filmed a light version and a dark version of the films and released them both. Try and recreate the choices the player had.