When the Zoroark silhouette was revealed, didn't Corocoro have their own reveal very shortly after? Same with the B/W starters, I think.
Breaking news comes both from this show and Corocoro, and they do sometimes reveal the same thing.
IIRC, Masuda showed the silhouette first, then fully revealed Zoroark at a later time. The difference here, though, is that Keldeo has already been revealed in CoroCoro, and will get a fully detailed reveal in the next issue.
I guess we just have to wait and see..