That would also support my suspicion that Canon is going to try to push RF APS-C users into buying FF lenses in lieu of providing a significant number of RF-S lenses, especially primes.
Basically, the two criteria I think are price and size. It's pretty easy to believe at today's lower sales volumes that Canon can sell a single wide-image-circle 16/2.8 to all customers more cheaply than they could make both wide-image and small-image variations. That might be true for a big range of focal lengths, actually. So then size is the next question: as you get more telephoto I think APS-C-only lenses could be substantially smaller than ones with a FF image circle. But for wide-angles there may be no notable difference. The 16/2.8 is mostly autofocus motor and control ring anyway, there's hardly any actual optics in it! :-D Even if the optics shrank to nothing the lens wouldn't be appreciably smaller I think.
So it might be that for some lenses Canon will expect the APS-C buyer to be happy with the FF lens. In some cases, maybe less than happy with size or maybe price, but still buy it. What they want to avoid is people not buying the FF lens at ALL, or worse yet, not even buying a Canon due to the APS-C lenses being too large or too expensive or both, so in cases like that they'd try to make an APS-C-only lens. That's just my guess from sitting through a fair number of product-planning meetings in Japanese tech firms...