That’s not how it works. New housing, even if luxury, provides options for wealthier people to buy who otherwise are forced to bid up the price of older homes and remodel it to their liking. New housing starts an immediate chain reaction where wealthier people vacate older housing in less desired areas for the new homes, thus putting downward price pressure on older homes. Our current problem is that for the last thirty years we have banned most new construction, resulting in a shortage of new homes.
We saw this dynamic play out during the pandemic when news cars were delayed due to supply chain constraints, and the price of used cars shot up.
I should have prefixed my comment by saying I'm not in America. In the country I live in, population growth effectively occurs by immigration of not-poor migrants, and that growth continues to outstrip supply. Sure, if you build more high-end houses than you need, you would see the effect you describe, but it's like emptying a swimming pool with a straw.
We saw this dynamic play out during the pandemic when news cars were delayed due to supply chain constraints, and the price of used cars shot up.