Whether or not you have a valid copy of Windows 7, the offer for users of assistive technology does not apply to you unless you actually use assistive technology, whether Microsoft's built in accessibility features or third party things such as screen readers, magnifiers, etc.
I am begging anyone who is not an AT user not to use this offer, which is being handled on the "honor system" obviously, if they are not a part of the target audience. Microsoft could pull the offer, or make the "proof of AT use" provisions much more stringent, if there are far more downloads via that channel than what they know to be statistically expected.
As to the reinstall after upgrade, some do, some don't. I'm in the don't camp. I work with the upgraded system and if I am having no stability problems I have no reason to go through that extra step. If I have a system that is having stability problems then I do. I can say, though, if you know you're upgrading a Windows installation that is already wonky in ways that you recognize, then I would immediately do a Reset with "keep my files" option just so you get a new copy of the OS in its entirety and that any even possibly suspect applications get removed (and a list generated of what's removed) as part of that process.
Brian AKA Bri the Tech Guy (my website address is in my profile) Windows 10 Home, 64-bit, Version 1709, Build 16299
Here is a test to find out whether your mission in life is complete. If you’re alive, it isn’t.
~ Lauren Bacall