The impression I got was that the laws work slightly differently in the EU, and nothing prevents them from pulling licenses from scrapped machines and selling them. I'm not 100% on that though, so it might not be true.
As for the Windows 7 to 10 upgrade, for the most part the free upgrade period is long over. There was some trick that you could do to still get it if your machine upgraded if it had certain accessibility settings turned on, but it looks like its only good for another month:
Here's how to get Windows 10 for free -- until Dec. 31
And I do think that machines that had previously been upgraded from 7 to 10 can now be re-upgraded from 7 to 10 or have a fresh install of 10. When the main offer was good I went to the trouble of upgrading all of my machines to 10 and then reverting just so I'd have the option in the future.