I think darkoath might have been the new miniature monday reveal it was meant to, just by accident a couple of days early. The reason I think that is because they always update the videos very last minute.. and while they must be prepared earlier I think the last minute web guys do not have access to the wider pool... it definitely wouldnt be a video for a month later.
I seem to remember AoS has had multiple miniatures revealed on monday before, so its not unheard of, in fact its one of the "problems" with the whole AoS vs 40k love thing.. since AoS started it has had more releases than 40k did in the same time period, however where 40k tends to have 5 articles per new kit, AoS has 5 kits for one article ( exagerating ofcourse )... not to mention ip licensing, BL and the community also focusing much more on 40k Spacemarines.
( disclaimer for those who not know me, when I say I think or speculate in general.. I rarely think Im right , I often have several conflicting theories of any matter at the same time. )