I’m pretty sure they’re holding What’s Opera Doc and The Rabbit of Seville back for subsequent releases … though that indicates they’re thinking of subsequent releases, which is a good thing.
According to The Digital Bits, Rabbit of Seville will be on the set. There’s lots of great classics (including What’s Opera, Doc) that didn’t make the cut, but I’m sure the future will be interesting…hopefully…
That Digital Bits link about has the full list of 'toons in the set, by the way.