I disagree. Homeowners of multi-million-dollar properties have something others really want — property — but they also usually don’t actually OWN the property; they have mortgages.
And if they sold their property, some of them would be wealthy, but they’d also be homeless. And as soon as they attempted to buy another property (or even rent), they’d be back to having very limited disposable income.
So yeah; they’re still middle class. Someone else is holding the purse strings; the purse is just bigger.