A confirmed ticket in R class (premium cabin) is a confirmed and ticketed ticket in the premium cabin. Payment for this premium cabin seat was a combination of money and a certificate (a GPU in this case).

AA is honorable when dealing with pax that have used confirmable upgrade instruments -- they will reprotect on other carriers in the ticketed/reserved premium cabin. UA used to do this but now has taken the position that they don't have to reprotect on another carrier, regardless of one's ticket type (full-fare, discounted fare, free award, paid + upgrade, ...). So, UA's unfortunate position is that they only have to reprotect you on UA and if you don't like it, they'll just refund your money. Again, doesn't make a difference if you're on a regular paid ticket or using an award or an upgrade -- they'll only keep you on UA. One can, sometimes, get a sympathetic agent to reprotect on a different carrier, but I haven't seen them recently reprotect a cancelled R seat into another carrier's business/first seat -- they MIGHT reprotect into a Y seat.