With these companies now saying do not upgrade the OS I fully understand why PG Music has said nothing about BiaB Mac 2019. It will be interesting to see if any other type of software companies come out with similar announcements.
MacBook Pro - Big Sur 11.0.1
Yamaha SLG200N
Arturia Keystep

Logic Pro X, BiaB Ultrapak 2020 Mac,
Xtra Styles 1 - 10. Loops-with-Style PAK 1 & 2. Multistyles PAK 1.