MS want everyone on Windows 10, they wanted people to migrate. Giving them a deadline of 1 year probably made alot of people move over, rather than waiting for today to do it.

Or prompted people to pay for Windows 10 if they weren't aware it was still available as a free upgrade.

Yes, it is a 'free upgrade' BUT don't use the option 'upgrade windows' in the install menu!!
this will scan all your software and get it saved... OK if you have a day to spare, and a few retries... :/

If your win7 PC has the registration code on it (that DOES NOT have the OEM in the numbers!)

then you can use this for win 10 make sure all your software is available on CD or USB so you can do a fresh install later...