I really don't understand the argument, to be honest. If somebody is participating in something with a perceived expectation, and then that expectation gets contradicted not once, but twice, why is it unreasonable to assume it might happen again? I'm not being facetious, I genuinely don't understand the line of thinking.
If they have a coherent set of values, then that's why. Then you have a theory of mind about the admins, and they weren't behaving erratically, but it was your original expectations that were incorrect.
I think I agree with you, so maybe you meant to ask someone else? Or you’re just supporting my argument, in which case I appreciate it :-)