It’s only lose-lose if they do Revan, same as a Mass Effect movie that does Shepard. Old Republic era overall would be fine.
I doubt they’d do a direct adaptation anyway. And even if they did the games aren’t canon anymore so they’re free to define it how they want (the people who’d be bothered would be a minority).
Well, of course, but Revan was a player-insert character, so everyone has their own view of what “their” Revan is. That’s why the TOR additions to Revan’s character were so poorly received. Any adaptation of the character will face the same issue, whether it’s adapting the same story as KOTOR or telling a new one.
I just mean the amount of people who have played the game and have strong feelings about the character two decades later is number that pales immensely in comparison to the size of the general target audience for Star Wars films.