The work is being done in close cooperation with Teck,

Teck knows everything that CUU management knows. They do not need the public release of the BFS to make an informed decision. I suspect at this point Teck is waiting for some more definitive info. like the Mira report, Titans, and perhaps several drill hole assays for confirmation to make a final decision/offer. Staying out now would be at your own risk of missing a possible buyout by Teck imho.