Yeah that last link is what alerted me to check further all the way to MS. It's been quoted on many places since. I can't see it taking months either but some time will have to pass. Boom and on 29th everybody has Win 10 is hardly plausible, they'd have to hire Santa to achieve that.
I haven't been able to detect any large chunks of download to my 8.1 to indicate MS already starting to prepare for upgrade and it should be at least 500 MB a day to get everything in by due date. So that theory may be false.