Typically, the originating mortgage company services their own loans for the first year, and some up to five years. Then, 90% of them sell to investors. That’s what happened here. The mortgagee (ie the homeowner) does not have any control over that process or who the loan is sold to. So one to five years after refi, that new loan could end up anywhere, including with Greentree. Refi if it makes sense to do so for rate improvement, etc. But not for this reason.
As an aside, when folks see in the news that China owns a lot of the paper on American homes, this is how that happens. Those mortgages are sold to whomever wants them. Kind of a scary thought.