This will all reverse in time. All the boomer classics will start to fall in value, much like the 50s cars have. Sure some cars appeal to multiple generations (I think S30z more so than others), I'm partial to a split screen corvette, the old Corvairs, the Chevy Nomad wagons, and some other muscle car era stuff (XA/XB Falcon Coupes - AU market), but I'm an early Gen Y kid (born 82) and a lot of my generation and later born kids ar into the late 80s / 90s stuff.
That seems to be where the growth in values will come from next. IMHO of course.
Jay Leno garage featured 3 Japanese classics and asked which had appreciated the most in the last few years. I was somewhat surprised by the growth, but it's highly subjective and doesn't factor in rare models (I guess) probably based on Hagerty data which is very US centric and not globally aware of certain makes / models..
https://youtube.com/watch?v=znzi-nxV0bA&si=AVbQgNZeo5XV6HJE