It really is manufacturer by manufacturer and product by product
RB-WAV-1385: Doesn’t seem to have a CAD / STEP file available RB-PIT-123: Doesn’t seem to have a CAD / STEP file available (though they provide global dimensions below)
Usually CAD files are not open source.I see that manufacturers often make the PCB layout open source but the CAD files are nowhere available most of the time.