I believe most people posting here would rather have a little more definitive time frame 1st quarter 2nd quarter excetera.
The problem is the false perception that once Microsoft has released an OS it is 'finished' and never fundamentally changes. That is very definitely not the case with Redmond's current policy of releasing into the wild and relying on the general user to be an expansive beta testing pool. In the past an OS went 'gold' and was released for 'safe' public use, only getting [mostly] simplistic revisions that were relatively harmless. [history demonstrates 'relatively harmless' is relative].
There has been a general change for people now wanting to embrace all that is new, no matter what it is...with the common misunderstanding that all that is new MUST be better. Mostly it isn't.
People claim that 10 is fantastic...the bees knees....and yet I have one machine that stoically REFUSES to update itself. Once it became non mission-critical. I forcibly installed a new version over the original so it was 'current'...and lo and behold...it still refuses to update.
My Win 7 is extremely long in the teeth as an installed OS, being imaged from a previous install on another box....so essentially been operating 24/7/365 for about 15 years... and yes, it has issues....Safe Mode does not exist anymore, but I get around it. Only time it gets a reboot is when I have an OOM issue with an old 32bit proggy that doesn't see all the RAM.
As for Windowblinds...it's possibly THE program MOST dependent on an OS to remain unaltered and not at the whim of MS to be constantly fiddling. It hooks into the shell on fundamental levels that a normal program has no reason to.
There will always be a 'lead time' between what Joe Public thinks is an OS and what becomes one that stays relevant long enough to have its shell revised.
There is quite a bit of difference between "well, 11 works on my machine just fine so it must be stable and capable of being designed for", and "11 works for everyone equally without fault and is ready for general use"....