Welcome to the forum!
Is it this bike?
https://www.cube.eu/en/2022/bikes/ur...-fe-bluenblue/
They call it the Road Race FE, but it looks like it has mudguard mounts and GRX, as you noted above. Tektro hydraulic brakes will be fine. I slightly prefer Shimano for easy maintenance bleeds with the screw-in fluid cup, but I've owned Tektro and they work well.
Note that, due to the current supply chain problems, bikes will often ship with slightly different components than originally specified. This may or may not happen with Cube. If you buy it from a local bike shop and can see the bike prior to purchase, you'll know exactly what you're getting.