Isekai can matter to justify the protag having a different attitude than usual for the setting, like a noble or princess who believes in equality and/or gay rights. Or for having extra knowledge from having played the game. Or from having been older before janked into a high school setting.
In MagiRevo, Anis's memories seemed somewhat hazy anyway. Conversely in the fanfic "Sanitize", the protag's medical knowledge is quite important.
In this case, Yvonne is making decisions in part based on her knowledge of the game, 'routes' and all, even though I have the impression she was just a beta tester and never played the whole thing, so she's overconfident. (Plus there's been deviation, like the 'mare' in chapter one.) Vs. IFTV, where Rei has a ton of knowledge and is specifically trying not to invalidate it before making her big move.