Remember what the anime does and what the games does is completely two different things (sometimes unfortunate). The anime takes things and material from the games but it doesn't exactly follow what the game tries telling. BW must have been an annoying experience for the writers with not only them having to delay the Team Plasma arc but than hearing about BW2.
They'll announce the games when they're good and ready, from the tibits of information we got about Zygarde's new forms if that's any indication of the plot's complication then I'd rather they focus on getting that down and making an intriguing announcement than them looking at what they have and slapping something together. Remember the "sneak peak" or ORAS? Do you want another one of those or do you want a trailer like we got for XY?
