I would be all for getting rid of the windows tag, it is a meaningless way to tag a question. The windows tag could be applied to any windows products, it does not define the operating system that the question applies to.  Used in combination with other tags, does not help much XP, 7, NT, 8, 98 , 95 , Server8 or whatever else there is.

A "Windows NT" tag would specify a specific windows operating system, that has features and functions that are unlike Windows XP or Windows 7 for example.   
 "windows nt" it is being applied for "nt" questions as it applies to the whole nt line of windows.  It is not Windows NT, it is windows nt.  It is not a synonym of win98.

There are huge differances between Windows nt (nt based), and Windows NT (the os), and between Windows Xp , and Windows 7 and Windows 2000.  They should never be combined under a Lump. 

Getting rid of obsolete, would be done when it is actually obsolete, a manufacture does not determine that something is obsolete for the Users.  I am all for getting rid of anything that is obsolete for all users, and keeping anything that users still use.  (I have seen situations where a product or software becomming obsolete is just the beginning for it)

I am all for getting rid of using the term windows-nt to define a Line of OSs that are Nt based, and replacing it with the actual OS item used.

I am all for , getting users to Stop using the windows tag, even though it is not likly to dissapear, and replacing it with the specific OS.

 This is important only for questions that are Just tagged, and the Q does not have the OS written into the question. 

What is done with it, I do not know.  I am just trying to cover what I see.