The sad thing is that this was all already implemented and done in Microsoft's second POSIX subsystem for Windows NT. It provided signals and process groups support for job control shells. It had a full control sequence interpreter for output and control sequence generator for extended keys. There were termcap/terminfo database records that people had added to other operating systems. It had a line discipline with "canonical" and "raw" modes. It had pseudo-terminals, with both BSD and System 5 access semantics.
I wish people would stop pointing at the Linux subsystem and using it as an example of the stuff Windows in general could do. The Linux subsystem is a subsystem. In NT terminology, that makes it practically a container. It's disconnected from the rest of the system. It can interact with the win32 world in only a few constrained ways. You can't deliver SIGWINCH to a win32 process!