So thinking, this is the first time Universal's really been "allowed" to hide SS19 from CityWalk, previously it was to show off Nick Studios and then access to BMG. So I wonder if they're looking to build a new shop/restaurant. Right now most of the area in front is take up my truck storage for the Hard Rock Live venue (tractor-trailers for show equipment, talent busses, etc). That can be moved parallel to the sound stages in previously guest accessible areas. Then that opens up a good-sized rectangle where something new can go.
For the discussion, I think there are two "replacements" for BMG
1) Something placed on the CityWalk plot between Hard Rock and HRRR
2) Something replacing the SS19 theater
#2 seems set, nothing yet and will likely be snatched up by production. #1 is the most interesting to me.