I had this question raised on my way back from Edinburgh to Peterborough last night; there was work going on that resulted in replacement buses/coaches from York to Leeds/Wakefield Westgate/Selby, and with a lot of routes and passengers that meant a lot of buses and coaches. Unfortunately with all the street works going on outside York station, and the multiple destinations, it was a good 500m walk north to the RRB pick-up point on narrow pavements - and plastic ramps covering up holes - that could not cope with the volumes of people. The area south of the station was used for tipping out bus arrivals, so at least there weren't two streams of passengers trying to get past each other! In those circumstances, what assistance could someone with severe mobility issues expect? Because I suspect there wouldn't in reality have been much, given the demands on staff from everyone else.
(Of course one solution would have been not to take the RRB at all and go via Harrogate and Leeds, but that would probably be invalid given an advance ticket predicated on taking the RRB for timing reasons. And it doesn't affect the principle of the question; that route might also have been affected)
(Of course one solution would have been not to take the RRB at all and go via Harrogate and Leeds, but that would probably be invalid given an advance ticket predicated on taking the RRB for timing reasons. And it doesn't affect the principle of the question; that route might also have been affected)