Upgrading to W10 after cut off date

Im running Windows 10 Pro an a HP Probook 4530s.
Due to bad support for the AMD switchable graphics, i want to sell the computer.
If i downgrade it to windows 7 using a macrium reflect image, since the PC was on windows 10 at some point, will i be able to initiate the upgrade after the cut off date to get back to windows 10 since its the same pc. MS should know that it had 10 before i assume?
The AMD drivers cause very slow booting and i cant sell the pc with that issue, also the fix for it makes battery life only less than 1 hour so that would make trying to sell it worse. So I plan to downgrade it to 7 before sale. But if I dont sell i want to get back to 10.

I expect that the Windows Update route for upgrading to 10 will be gone in a week's time, but I imagine that you will be able to use one of the other ways (see the tutorials) and that 10 will activate online, as now. ("Digital entitlement'.)

After July 29th, upgrading from Windows 7/8/8.1 will work exactly the same as it does now on the user's computer. The only difference will be on Microsoft activation servers.

After July 29th, you upgrade from Windows 7/8/8.1 to Windows 10. Just like now, Windows 10 will send the Installation ID to Microsoft activation servers. Just like now, if there is a matching digital entitlement for Windows 10 stored on Microsoft activation servers that will be retrieved and sent back to activate Windows 10.

The difference will be if there is no digital entitlement that was previously stored on the Microsoft activation server. Now, the server creates the digital entitlement, stores it for future retrieval, and sends it back to Windows 10 for activation. After July 29th, the server will send you to the Microsoft store to purchase the digital entitlement instead of creating it for free.