Apparently he had a chronic progressive type of MS. He may come to a platteau, however, as many progressive types do and be ok in his wheel chair for living life ok, for a long time.
Yes, if you are starting out RRMS, then you are lucky, as I am. I started out RRMS(lite) in 1964...no meds...turned SPMS in 1998ish and at 72, am still going strong.