They could easily extend it. They have to pick some type of time frame to start with. If they had said forever, and then changed their mind latter on down the road, and released Windows 11, people would call them on the free forever statement. This way they have options latter on down the road. In ten years or so they decide what to do. Nothings etched in stone as far as this goes.
Tenforums will be getting very long in the tooth by then. However, Sevenforums will still be going strong, I imagine, though
10 years is the standard already set with Windows 7. XP got more than 10 didn't it? If Microsoft commit ten years of support to Windows 10, then it is likely that a new OS from Microsoft could emerge in 5 years. Microsoft will design a large overlap of support years for OS transitions.
Of course, if Windows 10 is to be the last, then maybe Microsoft simply plans to choose shop in ten years' time.
If Windows 10 is their last names OS what is after
Linux? I will only be 77.
October 14, 2025
Seriously now and jokes aside, Microsoft could bring out "Updates"(updates in quotes because I don't know if update or upgrade is the better word) that would extend Win10's lifecycle beyond the 10 years.