The answer to this question depends on the knowledge and quality of engineers working on the kernel and the overall Executive. These continue to evolve with more advanced technologies, like VBS or the future usermode endpoints for EDR and possibly anti-cheat, pushing those out of the kernel, which presumably requires kernel work.
David Cutler is still there but working on other stuff, last I understood.
That does lead to the question of 'would they do it the same way and/or follow the NT OS/2 spec' to get a functionally identical Windows today.
Ironically, from his latest interview, he mentioned working on Linux on Azure racks that are actually repurposed XBoxes.
Cutler working on a UNIX-like system? Did hell just froze over and I missed it?
See the last 5 minutes from his interview, done last year on Dave's garage YouTube channel.