Gibson VOS guitars really aren't very "aged" at all, they just take a bit of the shine off the finish and tarnish the hardware a bit (some guitars have more ageing of the hardware than others, it seems to vary quite a lot).
So I think they'll be just fine in 50 years.
Heavier relic jobs like some of the Fender Custom Shop stuff.... I don't know. It depends how hard they're played, I guess. After all, there are real '50s guitars around which are still in great condition, so a relic which is only lightly used probably isn't going to get much more beaten up than it is now.
And, of course, the ageing is only superficial, they don't do anything which would compromise playablility - no knackered frets or worn-out pots!
