It skipped version numbers because of lazy 3rd party app developers in the time of Windows 95 / Windows 98 who coded applications to look for Windows 9* rather the discrete numbers, and this legacy code is still alive in some large corporate applications.
I think that's a myth. I'd be surprised there was much 90s software around still that could run on Windows 7 even.
What happened to Windows Compatibility Mode? That could have taken care of the supposed "9n" windows version problem.
Microsoft should have dropped 32bit flavor OS in Windows 7, but when 8 came around they wanted it to run on underpowered tablets, so they kept it.