My partner works for a small charity tied to a IT support team of 2 nerds, part of the office accommodation package that they rent. They were caught out by this yesterday when all their PCs and laptops went through the "upgrade" process, leaving them unable to do anything with them for hours. They then found that ther internet connection was unuseable and they couldn't access any of their files, which turned out to due to their bandwidth being completely overwhelmed by the automatic transfer of several years worth of local files onto Onedrive.
I know this kind of situation can be properly managed to avoid this happening in the right company environment. However, this is a charity run on a shoestring that hasn't got that kind of IT control or resources available to it and it can hardly be alone in this. They had no idea they 'agreed' to the upgrade. All their hassle could have been avoided by a less deceitful dialog box.