This line of thought really amazes me.
I mean, I'm one of those DMs that struggle to get to 4 encounters per day, let alone 6 (or 8!).
Still, my minmaxing charopian players have all selected shortrest classes.
Go figure. Myself, I'm not so sure. Instead, I would phrase it the other way round: Any long rest class would be severely "harmed" by a play style that matches the 6-8 encounter expectation.
If it's a maximized choice to choose a shortrest class in my 1-4 encounter day campaign, imagine how my players could wreck somebody else's 5-8 encounter day campaigns...!