from the OP. I have included into the OP. Here’s a quick synopsis:
On Saturday, UW first reached out to BYU. There was initial interest but also cautious because of PAC 12 policy that allowed for cancellation, up to Thursday, if a conference member became available.
On Sunday, BYU came back and said they wanted to wait for the CFP rankings to be announced.
UW’s AD could not wait that long and reached out to SDSU.
As far as the report that BYU had offered to play the game, if it was held in Provo, the AD said that UW never received such a proposal.