I tested several demos and the answer varies with the different Styles. Disable both RD's and RT's and the Style still shows the RT/RD instrument but nothing gets generated. When Erase Track is used and hitting the play button and nothing is generated. Hit generate/play button and the midi pattern is returned and generated.

Erase a RT and the instrument is removed and nothing gets loaded or generated but the option to erase RT is followed by erase midi data. Responding no to erase midi data and a midi instrument is assigned and the midi data plays. If there's no Real Chart generated, it's usually a piano assigned and the midi piano plays.

So the answer to the OP question is if a RealTracks Style is loaded, the RT's load but do not generate. RealDrums may load and play a midi drum. Unless other options are applied forcing something to play, the only sound generated is the drums track. There may be exceptions because the Style reacts differently if no Chords are entered than if chords have been entered onto the chord chart.

BIAB 2025:RB 2025, Latest builds: Dell Optiplex 7040 Desktop; Windows-10-64 bit, Intel Core i7-6700 3.4GHz CPU and 16 GB Ram Memory.