DL's website does suggest RS as an accommodation if someone cannot wait in the queue and it has been rumored that that will be an accommodation offered at WDW for those who no longer qualify for
DAS and cannot wait in the queue itself. Someone in the party would still be waiting in the standby line though in order for someone in the party to wait outside the line and qualify for RS. For an individual with a DAS, they are already being accommodated by the DAS. There would be no need for a RS to be issued.
The suggestion of RS as an option for larger parties I don't think is meant to be construed as a suggested or even possible way to bypass the 4 person limit on DAS. I think that's just referring to people who no longer qualify for DAS. If you have enough people in your party, then the individual who is unable to wait in the line could potentially wait outside it while everyone else waits in standby, then the individual waiting outside the line could ride through LL. The "larger party" aspect refers to the idea that RS wouldn't work for many smaller parties if there's not an extra adult in the group able to wait in standby (like single riders, an adult with a couple of kids, a party of 2 adults and the person needing to wait outside the line needs the assistance of the other person so they can't be separated, etc).