[QUOTE=Dee;2755695]The important words in that sentence is [B]‘upgrade to Windows 10’[/B].
People who have already joined the Windows 10 insiders, and running Windows 10, wont upgrading to Windows 10, as they are already running Windows 10.[/QUOTE]
Going from Win 10 preview to RTM would be an upgrade to the final version, just like it would for 7 or 8. I believe Microsoft are trying to clarify the situation by saying you will get if free from 7 or 8, not 10 preview. So there is even less evidence now than before that installing the preview is a free ticket to a full license.