I'm absolutely not an internet expert (and my good CCIE friend is gone right now), and I haven't e-mailed or chatted with Shawn or anyone at CW about this; but it seems obvious to me why Shawn called these (technically quite incorrectly) Class C networks:
They are C-like subsets of a huge Class A network--ersatz Class Cs.
The most useful and distinctive aspect of C nets is their having a mere 8-bit local range of addresses, thereby avoiding waste (which used to be extremely common--we'll never run out of IPs, after all, there are soooo many --assigning a roughly 64K IP B network to a company that needed, say, 1000 addresses).
Cogent is doing with its own network that same thing that ICANN does with the Internet as a whole--breaking it up into smaller chunks that can then be distributed on an ad hoc basis as needed. So one could think of these as Cogent Class-C networks, functionally speaking. That's why Shawn showed the final number in the addresses as .XXX -- an 8-bit local range, which is the business end of a Class C address, even if it it's an ersatz and not a true Class C.
I probably don't have to ask, but if there is a big functional difference between a true Class C and these ersatz Class Cs or whatever one wishes to call them, please let me know. I've been trying to understand why this is such a big issue here--seems trivial to me, but maybe there's a lot more to this than I realize.
A further question for those who are CCIE, CCNA, or equivalents: I've also heard it said that the whole talk of Classes is now obsolete--is there any simple explanation of what that means? Is it incorrect? Or is it simply the application of ICANN's recognition that there are too many A's and B's, and not enough C's? (This may be too off-topic--feel free to PM me, if you wish.)
Note for RSG2: I think Shawn does indeed have 1K or so IPs, even for a mere 30-40 servers, in that CW uses multiple IPs per server, giving reseller accounts their own logical nameservers, e.g., with a pair of IPs for each reseller. (I think some resellers get 5 IPs.) Also, SSL most conveniently requires a static IP. I think they wanted a bunch of spares for future expansion, as well.
And thanks again for being a rational critic of Cyberwings--not quite alone, but not exactly a crowd either.