Even if they were full professors, 25 seems like a literal drop in the bucket. There are 187 R1 universities in the US. Competition for professorships is so intense that a lot of people look at grad school as a sucker's bet. I'm happy for these people and for Austria, but I don't see a real news story here.
The thing is that professors and research groups aren't fungible. Each one that moves represents a nontrivial loss in expertise for the US in some field. There are only so many groups doing basic research into materials science for microelectronics, for example---certainly not at all 187 R1 universities. But something like that is a strategic asset for the US, to the point that there's a DARPA office specifically to fund that work (https://www.darpa.mil/about/offices/mto).
Austria has 9 million people. Scaled up in proportion to US population, that's the equivalent of ~940 academics. Still not huge, but a somewhat bigger drop.
What is meaningful, I suspect, is that this reverses the usual direction of brain drain. If this is not a fluke and that reversal gets consolidated, yeah, that's really bad for the US. Alongside the $100.000 H1B, there is a chance that this could durably shift Silicon Valley-style creativity outside of the US.
