Another thing to consider is this: All of the existing design/tooling/R&D they have, that people keep bringing up in the argument for "reusing what they have"... it's all based around a figure that you put another figure inside of.
Thus far, the general assumption is that Banner is inside the HB 2.0, not Tony in an existing armor. They might make a lot of figures from IW, but I doubt we're going to see another Banner figure.
No current Banner figure to put inside the HB2.0 means there's no reason to allow a figure inside the 2.0, which means there's no reason to use the structural tooling from the 1.0.
Additionally, the HB2.0 may actually be smaller overall (in the movie) if it was designed with Banner in mind, because he wouldn't be in an armor. inside another armor.
Frankly, I'd be thrilled if this were a PP figure/statue in scale. I love my HB 1.0, but we've all seen how limited the posing options are, even with articulation. Shave a few hundred off the price, don't make me wait 3 years, and I'll take a less-articulated second HB.