Agreed. The university unquestionably has the right to prevent you from connecting a device to its wired network. The only question is whether it can use wireless "self-help" to prevent you from doing so.
At my university, the wireless APs would scan for others and try to detect if they were on-network using a student's auth. They'd tell the student to remove the AP if they wanted to continue to have access to the school network. Wireless, off-network hotspots were allowed, provided they weren't impersonating the school network.