It would not hurt to leave it installed a little longer till it's for sure that it won't upgrade.
Windows 10 free upgrade is still available using Windows 7 and 8 product keys | ZDNet
Since the above link shows that people are still able to get free upgrades, it would be good to give time for Microsoft updates to clear everything out for sure.
Wayne Sallee
Wayne@WayneSallee.com
Wayne Sallee . Com