Joseph: It depends. The Rav points out that there are two types of psychological assumptions in the Gemara. Some are just the Gemara noticing the psychology of the people around them (for example, the assumption that a person won’t lie when it is obvious that his lie will be discovered) and those can change over time (and therefore any Halachah that sprouts up based on those assumptions can change). This isn’t radical. Rishonim have said this already.
The other type of assumption is one that is built into the Briah (I believe the Rav called it an ontological truth). Those (his prime example of it was the Tav Lemeitav assumption) and those cannot be changed, no matter what we notice in the psychology of those who surround us.