Source: https://oag.ca.gov/news/press-releases/attorney-general-bece...
I have a 30 year mortgage, but every 5 years I have to "renew" it. At that time, I have to renegotiate the rate for the next 5 years. As part of this negotiation, I can just switch banks if I want. Or to a private lender. Or to anyone really.
It seems weird to me that you are beholden to an entity you've never signed any contract with.
I would expect if WF decided your first loan met their purchasing criteria, your refinance would get the same treatment.