I had to take a class in Windows Licensing because it's very confusing. Here's what you need to know.
Windows 10 OEM activates for a single computer.
Windows 10 Retail activates for one computer at a time. When you use the product key on a new computer, you have to deactivate the old one, or call Microsoft on it.
Windows 10 VLK is a key that is generated for up to x number of installs (pricing varies). Same rule above applies when you reach the max number of keys.
The way Windows licenses a computer is by sending the motherboard information to Microsoft during activation. This binds the product key to the motherboard so you can replace any other component (not the motherboard) without having to re-activate. If you replace the motherboard, you'll need a license or call Microsoft and tell them why you replaced the motherboard. They are usually pretty good about it and as long as you aren't replacing the entire computer, you should be fine.
To Microsoft, a computer is the motherboard as it is what all the peripherals connect to, if a motherboard dies within a short period of time, it's usually excusable by their licensing agreement, but you have to call them and tell them whats up.
When you do a fresh install from a disk, as long as it is the same edition of Windows 10 as previously activated, your computer will automatically activate shortly after you sign in. This means you should be able to bootcamp Windows 10, remove it after a while, wait months, reinstall it, and it should activate without asking for a key, I have not tested this so it's just theory to me.
Pro tip* if it isn't you can grab a generic license key for your version and it will configure windows then activate with the product key assigned to the motherboard for the edition it changed to.