That message basically just means that Windows uploaded its activation status to your microsoft account for that computer. So, if you were to completely wipe that computer, maybe even swap a drive or two, install Windows from scratch skipping entering a key during install and log into a microsoft account, you should find that windows automatically reactivated itself. This is saved for each computer individually.
And while we're on the topic, something else that might be helpful is that any computers that came bundled with Windows 8 or later will have their key embedded in the firmware. So if you were to install windows from scratch on one don't be surprised if the installer doesn't even ask for a key, and this is still true if you install Windows 10 on a computer that originally had something older since upgrades were free. Of course, that key will match the edition of Windows that was included - which will most likely be Windows home unless it's a really high-end business computer. If you later decide to upgrade that installation to Pro, this is when the license being tied to your account will come in handy since immediately after you reinstall and sign back in Windows should just upgrade itself.
<Insert passage from "The Book Of Chrome" here>