Simply to be helpful (and not post disrespectful detritus in your thread. . . *cough*trashmanf*cough*), I'll go ahead and answer your question.
No. Ellusionist started dropping hints about the Shadow Masters early on this year, before T11 was even a gleam in Bayme's eye (or at least way before the first T11 trailer went up). My guess is that the shadow masters were supposed to resemble the Black Ghosts enough that they could almost be considered a reborn "second edition," with a lot of twists and nuances to make them totally different. That's just a guess on my part. But, to answer your question, no. The Shadow Masters and Black Ghosts have been in the production process since long before any of us even knew that a new dealer was on the horizon.