As far as I know, the brucellosis confirmation has only affected the FlyingD ranch to the point of closing it down to harvest and I believe it's keeping any bison from leaving that ranch. The others now have to run blood tests on each animal before they are loaded onto trucks and leave the property. Not sure for how long.
Most of these larger ranches mainly have a commercial interest in bison. My understanding is that the prices for bison meat is higher than normal these days and the ranches are getting more $$ for the animals at market than selling them to us.
The Upper Canyon folks are great too. Good people. They have a sweet piece of real estate.