While I like your idea, it would require refactoring how all room-to-room movement works completely - which is a big ask! I do find your idea fun though.

But as it is, working as intended - a waylaying thief is waiting for you, so when they see you, they are ready to (with thief reaction spead) immediately interact with you.

Otherwise this would open up issues of all pending room-entry abilities/afs.