Although technically correct, Windows NT 3.1 was based on OS/2, its predecessor. So although there is no direct correlation about a numbering scheme of NT version 3 following OS/2 versions, indirectly one might say there is (very loosely). I'm a former NT/Windows Server admin and supported OS/2, NT, and Windows (in addition to flavors of DOS back to version 1) and still have various copies of the software including a shrink-wrapped new box of OS/2 version 2.0 (early 1990s) that I never opened.
Yep, you make a good point about the (loose) connection to OS/2 versioning.