I should think that if Nokia is announcing a device at the MeeGo Conference, the software on that device is officially MeeGo. I expect Intel would go through the roof otherwise.

So, it may be that the next Nokia device runs "a revised Harmattan with MeeGo compatibility layers and an exception granted by the MeeGo TSB", but if so, that official exception means the software stack has been accepted and stamped as officially MeeGo. There will still be debates over the software's pedigree, sure, but it'll have its papers.