I’ve seen a screenshot of someone’s return to queue pass that was issued to their Disney app account. So, yes, it does exist as something separate.
Wow! Question: were they in line first? Did they leave the line and this is the method of re-entry? I sure would like to know more.
DAS is not RTQ, and RTQ isn't used for AQR. (Oh, these dumb, confusing acronyms... Do better, Disney)
Here's a case of when RTQ was used for our family that did not have DAS at WDW. My daughter uses a power wheelchair, and we went to ride Star Tours in May. They always route wheelchairs down the LL and then through a second split for wheelchairs for entry. On this day, there was a longer stand-by line, so they gave us a return time. They scanned my daughter's phone, added our family, and assigned a return time of 15-20 minutes. That time showed up in MDE.
A handful of rides (Small World, Jungle Cruise, etc.) have specific paths for power wheelchairs, and if those get backed up, they can provide a return time. Offering it outside of wheelchair use would be rare, but the tech has long existed for it. I guess that this is what will be scrutinized by the CM's supervisors if someone asks for it and tries to circumvent the line.
For all other rides, we are on the same playing field as everyone else.