If you use RealBand you can set it to 24/48 then it will generate them up at that rate.
The Plugin should have this feature soon so it will generate the tracks up to the same bitrate as the DAW.
But it will be inevitable that the RealTracks/Drums will become 24bit, it's just PG is a bit slow but they will get there.

TEST:
I converted a RealTrack to 24/48 it generated fine in RealBand with it set to 44/16 or 24/48 but Biab just had noise for the audio.
Some time back I tried it with MacBB and it was fine.

Attached Files (Click to download or enlarge) (Only available when you are logged in)
Realband-24bit.png (29.34 KB, 85 downloads)
RT433-24-48.png (43.38 KB, 85 downloads)
RB-RT433-24-48.png (121.21 KB, 85 downloads)