Woocommerce customer role doesn’t change if user is already a subscriber [closed]

While WC is off topic, and I am not going to dig into how it explicitly works, in general wordpress roles are just a semantic way to call a class of permissions and users probably can not belong to two roles at once (this is an observation based on user management UI, not on whether it is possible to somehow hack something in the DB or via code), therefor if the user already exists it is just not obvious what to do if it might be better assigned to some other role. Not surprising that if a customer of a shop is already a user on the site, WC does not modify it in any way.

So this is not so much about wrong and right but more about you looking for information about customers in an admin screen that is meant to manage user permissions and other non shopping related attributes