I think your first suspicion is the most likely cause, especially in view of the current scarcity or nonexistence of those roses, but I'll look into all of the possible causes. I don't recall those particular roses exhibiting RMV symptoms, although I have tons of other roses that do occasionally display the peculiar RMV variegation in their leaves. It seems to have no effect on their general health.
I have some of those crazy Queen Elizabeth roses too. According to Ray Reddell, it's one of the roses that's grafted in order to keep it short, in contrast to most other roses. I have one grafted one, which stays at a manageable height. When I discovered how easily the cuttings could be rooted, however, I plunged several into the ground in various parts of my garden, and those grew into monsters. I prune them down to 4 or 5 feet every December, and by April or May they're at least double that height. One is actually as tall as a nearby tulip magnolia. Lagerfeld does the same thing in my garden.
