Shroob
Sup?
You say tomato, I say tomatoe.Probably because they were farther in development with Roy and Ryu, who were both released almost immediately after their reveal. They didn't really need a third reveal.
And Cloud was revealed in November, not September. They may have not even had anything ready to show at that year's E3 in the first place. They did reveal him before the other two characters in Smash 4's second "wave" of DLC, so they still have him priority in a sense.
The point is, we have gotten "Enormous" reveals outside of E3 before. I feel like people jumping on board to "It's gonna suck!"-ville are being a bit too fast. Sure, it "could" suck, and it very well could be a low-key reveal, but let's not assuming that it will either.