I used to think the same thing before I made the choice to legitimately buy my AVP Preds.
Thing is, a re-release/update really would piss people off who payed a lot of money for their older figs. Some of us on the board who would know ahead of time could quickly flip the old ones on the Bay before too much word got out on the new ones, but most people might not be aware of this until the new figures were made available for PO. Then, they'd be stuck with the older obsolete figures without being able to sell them for a decent-enough dollar to replace them with their new counterparts.
Having that said, I'd still be all in favor of re-releasing all the old Preds. Doesn't mean it'll happen.