I have dealt with collectible cars my entire life. I have spent my adult life appraising cars, so I might have a clue. Everyone is entitled to an opinion, but ultimately the value is set by the market.
I was born in '76. Age has nothing to do with appreciating their past achievements. I am not a fan of the new GTO. It was/is too bland for the drivetrain. The same was said when the new STi was deduted.
As a die-hard Pontiac lover it is hard to see it go. My first car was a 67 Tempest which I still have. Pontiac was the tuner car of the mid 50's through the 70's. The block for their first V-8 (287 ci) was the same one that became the infamous 455.