As someone who has done some OS dev, it’s not likely to be of much help. DOS didn’t have much of any of the defining features of most modern OS’s — it barely had a kernel, there was no multitasking, no memory management, no memory protection, no networking, and everything ran at the same privilege level. What little bit of an API was there was purely through a handful of software interrupts — otherwise, it was up to your code to communicate with nearly all the hardware directly (or to communicate with whatever bespoke device driver your hardware required).
This is great for anyone that wants to provide old-school DOS compatibility, and could be useful in the far future to aid in “digital archaeology” (i.e.: being able to run old 80’s and early 90’s software for research and archival purposes on “real DOS”) — but that’s about it. DOS wasn’t even all that modern for its time — we have much better tools to use and learn from for designing OS’s today.
As a sort of historical perspective this is useful, but not likely for anything else.