Microsoft may be downloading Windows 10 to your computer without your consent.

[m654321]

OldGuy...

The title of this thread is what I find misleading as if it happens if you do not reserve your copy.

I agree, the title appears to be a statement (though somewhat tentative) rather than an open question. 
Either way, I wouldn't worry at all.  I reserved my win 10 upgrades for both win7 & 8.1 VMs on setup (1),
indicated in the footer below, though have since cancelled them.  For the UEFI win8.1/LL2.6 dual-boot in the
same setup, I have let Win 8.1 run with the upgrading process.  The win8.1 part of the dual-boot now seems to be ready
for upgrade as a file of 2,706 MB is now present in my Windows Update window.  However, the OS appears to
firmly remain as win8.1, and will not update to win10, until I click on this file to trigger the download and install process
of this file and its contents.  Microsoft doesn't appear to be adopting an upgrade-by-stealth tactic, at least from what I gather...

Regards
Mike