Yes that's exactly it. If you offer a PC builder an i5 or i7 at a price that is much closer to Pentium prices, what do you think they'll do?
Drop prices on the quads and ULV's...and omg suddenly pentiums and celerons show weakness in sales? Is this a surprise to you, I really hope not.
Very creative, but not supported by any facts.
A more likely scenario is that tablet sales have reduced demand for budget laptops the most, while higher end PCs are still safe.