Well this sounds interesting, I wonder what changes they will make to Windows 12. They should take a look at macOS for clues. This should be indeed closely monitored. Windows Defender should of course not get any preferential treatment.
I really wonder how this will work. I hope it won't dumb down security tools, I mean most of the security tools on macOS aren't exactly that impressive. But if it can make Windows more stable, it's at least worth a try. But M$ needs to make sure that security tools can still block stuff like keylogging, code injection, outbound connections and file encryption. Not to forget about monitoring process execution, service/driver loading and registry modification. Think of the stuff that a tool like AutoRuns monitors for example. https://www.softpedia.com/get/System/System-Info/AutoRuns.shtml