What Antaran says, that as long as you register the C6 Pro and get the serial number in your account they don't make a distinction on where you got it for the upgrade.  There is a long thread in the members forum.  But at worse case call/write to sales and let them confirm.  Then you should be able to get the upgrade to 7 Pro and a free upgrade to 8 Pro when its release by purchasing during this special offer.  Just have to join the plat club to do it.