Because the requirements of "192-bit mode" for WPA3 Enterprise fall on not only the actual WiFI but also the backend identity providers, you are explicitly not allowed to do this for Eduroam unless you also provide a parallel WPA2-style (thus WPA3 compliant but not "192 bit mode") WiFi for everybody whose home institution isn't the US government.
Lots of institutions have Eduroam set so that students (and academics, and everybody else like me) are just authenticating against their Windows domain controllers, so going to "192-bit mode" would mean ripping out a bunch of stuff, replacing it, writing fresh documentation, testing thoroughly and then authorising, but since we're talking about the backend every educational establishment in the world would need to do this before you can ship WPA3 192-bit mode. So, that's not going to happen.
Sure, it's just interesting because this seems like just a straight up good idea for authenticated WiFi, but because of the need to significantly change the identity backends it's actually not practical for large federated systems like Eduroam.
Lots of institutions have Eduroam set so that students (and academics, and everybody else like me) are just authenticating against their Windows domain controllers, so going to "192-bit mode" would mean ripping out a bunch of stuff, replacing it, writing fresh documentation, testing thoroughly and then authorising, but since we're talking about the backend every educational establishment in the world would need to do this before you can ship WPA3 192-bit mode. So, that's not going to happen.