That's really an error with the JP franchise from the very first movie, so at this point it's set as the canon franchise appearance of many of the animals or even animal types in the series and frontier really have no control over it, unless it's for creatures or types of creatures who never appeared in the movies with pronated hands. I wouldnt be surprised if they are pretty much contractually obligated to stick to certain things with the appearance of many dinos.
As much as I'd love to see this, as I'm all for more scientific accuracy, I don't think this is something they can just switch on and off... there would probably be a lot of work involved; altering the models and possibly the animation... and that's a lot to do for something that isn't lore accurate...
Well then i hope you understand its extremely unlikely to happen, as DNT said, they would have to rework the models and change all the animations, which is far too much work for something theyre likely not even allowed to do. The resizing is nothing compared to this.