Sorry, I'm just not seeing it.
Deculture came in 6th when shown in December.
Broadcast came in 2nd when shown in April.
One can assume that positive reviews and word of mouth about the Deculture cut lead to the increased ratings of the broadcast cut. Unless someone does an extensive survey, there is no way to really prove this, but one can make a safe assumption. Once again, if ratings go down for episode 2, it will say something (though, I am wondering if they count DVR recordings in the ratings, they don't in the US).
Your Macross Plus/7 to Western/Eastern tastes analogy is totally out of left field. Macross 7 hasn't seen release here, how can we really know how it would do in NA? Hell, Kawamori himself stated in an interview he had NA in mind when developing the series.
I'm not a fan of Mac 7 myself, but what the heck do I know? It may be huge here.
Whatever the case, it doesn't really matter. Its Macross, I'm pretty sure if it gets mediocre ratings, they'll run the entire series.