Your scenario could happen if the contract between CGC and Marvel expires and is not renewed.
That's what happened to the Stan Lee contract. That's why they can't use his name or likeness on the labels currently. There is still a chance this will change.
I think CGC should offer a $5 credit for any book that can't be given the same label upon reholdering.
I like the option of the label because you don't have to get it if you don't want it. However, if used properly I think the label adds more than $5 value to the slab. Slabs with Stan Lee labels carry a premium right now.
It was a great idea by CGC. Imagine how many Hulk 181s will be reholdered to get a Wolverine label.