Interesting read here:
Microsoft Backtracks On Windows 10 Forced Updates - Forbes

after many upgraders had problems:

I had to upgrade through windows creation tool as i am still getting messages that my reserved upgrade may be here in days or weeks!!Used it for 2 days and had quite a few niggly problems-couple of browsers lost customization settings, 2 BSOD etc,so imaged back to windows 8.1,all good now and everything working as it should be.