At this point, they could likely decompile MacOS classic and rework it to give it modern memory protection, virtual memory, preemptive multitasking, and networking.
I assume booting an OS with a mere few megabytes of RAM footprint would only take milliseconds?
It had most if not all of that.
It had networking from the start with AppleTalk, later Ethernet and internet with MacTCP.
MacOS 9 had a preemptively scheduled kernel.
The problem is having that and supporting the software ecosystem, which depended on cooperative scheduling without having memory protection.
MacOS 9 ‘solved’ that by running the classic OS in a single process. It had APIs for creating preemptively scheduled threads, but those threads were limited in what they could do.
Haiku specifically does not accept AI-generated code.
I expect if you use AI to explain how to write it and then write it yourself that would be okay.
You need to be able to explain your work without just pasting in what Special Needs Wintermute says.