If I'm honest, we all lust after the stuff we couldn't afford ten (or more) years ago. Today, that sort of stuff is usually a fraction of what it cost then, and we've generally got more disposable income to throw away on bikes (if only because we've been riding sufficiently long that we know it's a life-long thing).
The same will therefore be true in another decade or two. Many retrophiles will have got bad backs, painful knees etc, and will happily move to the latest full sus whatchamicallit. Others will still lust after the same stuff they do today, much as a generation of road riders can still be found restoring bikes from the 50s and 60s. Finally, there will be a group who are poor and/ or new to the sport today, who may find themselves lusting after Indy Fabs, Turners, Mavericks, Spots etc in the future, as that was state of the art when they started riding. As with today, people will have moved to newer things or moved out of the sport, providing a flow of these bikes to satisfy demand.