I'll be honest, as much as I was against the whole "Lion Preds, Tiger Preds, three-legged Preds, oh my!" approach from the original draft; I'd've much preferred that to just more pred dogs and another giant predator.
However, the fact is, the whole GM/Upgrade aspect is largely responsible for the fans' backlash and so it needed binning. I can see why the studio intervened, but the film was on a hiding to nothing from the off, sadly.
RE the monkey pred leaks: The slender arms look not too dissimilar to the 'remains' you can see on the original Coyle death pic from the first slew of leaked pics, IIRC.