On the contrary, high-status people can countersignal by publicly changing their mind on things in light of new evidence.
Sometimes. In particular circumstances. With difficulty. Even in circumstances that are abnormally in favour of sanity the status signal is still arguable. But note that effectively gaining social power isn't about just signalling high status a lot. It's about navigating social interactions with whichever signals are most effective. Someone who only signals high status comes across as 'rigid' or 'brittle'. I suggest that much of the signalling benefit for mind changing is actually signalling competence and increasing likeability rather than by directly signalling high status in the moment.
Thus spake Eliezer:
It seems that many here might have outlandish ideas for ways of improving our lives. For instance, a recent post advocated installing really bright lights as a way to boost alertness and productivity. We should not adopt such hacks into our dogma until we're pretty sure they work; however, one way of knowing whether a crazy idea works is to try implementing it, and you may have more ideas than you're planning to implement.
So: please post all such lifehack ideas! Even if you haven't tried them, even if they seem unlikely to work. Post them separately, unless some other way would be more appropriate. If you've tried some idea and it hasn't worked, it would be useful to post that too.