The rugged "Austin Beach" NUCs will be Intel's first fanless models to integrate 15 W Whiskey Lake CPUs. As far as the modular design goes, the upcoming NUCs will come with a special motherboard that can connect to replaceable Compute Element modules, which feature soldered CPU / RAM / eMMC storage components.
https://www.notebookcheck.net/Intel-to-release-Austin-Beach-fanless-rugged-NUCs-with-modular-specs.445728.0.html