Fudzilla already covered the announcement of the NUC and NUC pro, and the ROG NUC. We were assured that the 2.5L ROG NUC will remain the fastest gaming-oriented device and that, at this plan, the company doesn't plan to develop the successor of NUC Extreme 7.5 liter.

Asus has announced ROG Strix G16CHR, its 7.5-liter desktop that comes with an air and water cooler and hosts up to Intel Core i7-14700KF Processor 3.4GHz (33M Cache, up to 5.5GHz, 20 cores), NVIDIA GeForce RTX 4080 16GB GDDR6X 3x DP, 2x HDMI, and up to 64GB RAM in 4x DDR5 U-DIMM slots.

In order to update the NUC Extreme, one needs to swap the compute card, and there is no card based on the Raptor Lake refresh Core i9 14900K processor. It would make little sense to update as the performance delta would be minimal. Updating GPU always brings more speed to the game, and getting one of the 4070 or 4070 SUPER cards sounds like a decent update, considering that one had 3000 RTX series inside.  

The next generation Arrow Lake desktop CPU is most likely sitting in a new socket, making updates for NUC Extreme owners unlikely without getting the board or a compute element that would fit the design.