Consider:
---
sealed interface Intf permits A, B {}
final static class A implements Intf {}
final static class B implements Intf {}
private int test(Intf selectorParam, Boolean b) {
    return switch (selectorParam) {
            case A a when b -> 2;
            case B b -> 1;
        };
}
---

This used to compile as exhaustive, although it should not.