Yeah I reckon Quantum will still be available, just not through dealers anymore. It's a popular oil in BMW and Merc communities as well, so can't see it going anywhere.
I think VAG are just standardising all their fluids under one "G" umbrella, and it looks like Shell outbid Fuchs on the oil. Which is no bad thing as it's probably Shell Helix Ultra in a different tub.
It's a £50 oil change with a filter, full retail, which isn't too bad tbh. If my normal parts chap was there, he'd have done both for £40, but no discount from the newbie on this occasion.