I intend to to upgrade from BB 2023 Pro with Real Band to 2024. I am also interested in the pack "XPro Styles PAK 6: Progressive Rock". Is there some bundle upgrade option that includes that pack, or shall I order that pack separately?

The answer is : separately. But with a drop in price until the end of December.

https://www.pgmusic.com/forums/ubbthreads.php?ubb=showflat&Number=788719&page=1

Thank you for the information. Separately will be then.
I guess that by Progressive Rock they do not mean Yes, Genesis, Rush, ELP, King Crimson, Marillion, Transatlantic, The Flower Kings, Dream Theater, etc, but the demos seem to be more promising than the usual banjo country bluegrass and jazz styles 😃