I understand that NR-U is a full implementation of a 5G base station (and client handset/CPE if you can find one that actually implements NR-U!), and therefore you will require patent licenses for the full implemented stack.

In an ideal world, your radio manufacturer and software vendors would have appropriate patent licenses in place.

For this and other reasons (handset support being commercially problematic since carriers want to preserve their dominance), I don't see NR-U really replacing Wi-Fi. The friction to joining a device to a network is also far higher, and there's much more complexity in running the network and architecting a suitable core network and user plane functions and keeping it all running. WiFi really is a lot simpler in many ways.