Foreign students are not stealing “slots” from Americans. If anything, their tuition dollars make more slots available.
The money might be going into nicer buildings or administrative costs, but it's also a white elephant once the foreign funding dries up as the domestic situation improves for many internationals. After which then these universities find themselves in major trouble.
It's probably true but not really meaningful in the broader context.
With the current easy money federally backed loans US university funding model the foreign students are just easy money on top of an already screaming money printer more than a noteworthy subsidy of their operations.