AFAIK, the Volvo P1800 has always had a bit of a following, just like Citroens. A bit on the eccentric side I'd guess.
As you state, the DeLorean has always been somewhat of a collector car.
I get all the others...but the Prelude? Not getting that one. That would be its fifth generation. If you "de-badged it" it would be a wholly unremarkable old 2-door coupe. Nothing special except, as the British accented reviewer says, remarkable build quality. Yes, just like other Hondas and Toyotas of the era.
All the others on that list--quite distinctive in their styling and cache which aids in collectibility and price. But the list isn't what's good or not, it's their prediction of what is in the rising prices of a bull market. Each one has their own following and I bet, an online forum or club somewhere.
Who knows. The best anyone can do is a crystal ball.