Forgive me my possible ignorance, having bailed to the Dark Side (Apple) some years ago.

Would "no longer support" simply mean no more of their dam "updates" and the guys with the view of the Ganges no longer "help"?

Sounds to me like your OS and your paid-for Office suite would still work just fine after the Microsoft Rapture. At least until something takes a dump outside your ken to repair, I'm seeing an up-side to that.