I think the main issue here is that children, at such an impressionable young age, find it much more difficult than adults to distinguish between fantasy and reality.
Yes, it is a worthwhile and praiseworthy effort to try to provide Jewish kids with good, clean entertainment (G-d knows how bad the Disney and Pixar movies have gotten lately). However, if it means that our children come away with a misconstrued idea of how the Purim story happened, or even worse, come away thinking that the Purim story is just as much a fiction as a Disney story, then that's a huge problem.
When will people realize that banning everything is not a solution? we need constructive outlets in the 21st century, this isnt the shtetel!
The avg rebbe or morah in yeshiva etc does way worse job of confusing kids with misguided meshalim, sipurey habesht that may or may not be true, hashkafah delivered wrong, lack of attention to individual levels of belief in god etc etc etc.
I suppose you're right that changing the story does have its cons, but I would assume that most kids know the REAL story and putting THAT on video is less engaging.
Or maybe kids think that the story of purim is about fireworks, costumes and getting drunk
