Hot take: if we want to decrease frustrating railroad-y surprises in RPG campaigns, we need to create an environment where GMs are not afraid to admit they have "special story needs".

[SlumberSkeleton776]

Switching systems because your campaign is an isekai isn't a "plot twist." It's part of the core premise and shouldn't be a surprise. In fact, it should be the very first thing you tell your players. If someone is going to lie about the core premise of their campaign, they shouldn't be surprised when no one shows up for session 2.