Names we'll prob never see from Canon -
4D - four also reads as death in Japanese.
8D - 2 x 4 = 8 still a multiple of four. Superstition may keep this name at bay! Also sounds like you're saying 80.
I live in China(same ideas about the meaning of 4 or "si") and this is not as big of a deal as people make it out to be. Nikon already has a D4 as their flagship. My building(and most others) have a 4th floor. My apartment is #4..... etc.
"Si," depending on the tone it is said in also means "temple, silk, thought/think, tear/rip, personal, then/this, feed, similar and many, many others.
Yes, there is some truth to the idea, but I think the Nikon D4 proved that it is definitely not out of the realm of possibility for a camera to have a "4" in the name.
A valid marketing reason to ship the premium APS-C offering with a new name is this. If the new camera is a feature-laden as we hope, it's going to need a higher pricepoint. To name a significantly higher priced release as the 7DII will elicit howls of protest. "Look how much they've raised the price of the 7D!!!"
But if it's skillfully repositioned as an all new model, the grounds for grumbling will be lessened. The 7D classic may even soldier on for another couple of years...who knows? It's still a very good camera which has aged remarkably well.
I think this is spot on. If Canon wants to make the end all be all of APS-C cameras(which I believe is what they should do) they will probably want to position it well over 2000 dollars. A new, higher level name will facilitate this better than a simple "II" designation.