That's actually a very good idea. Unfortunately, designers did limit themselves on placement if they do do FJ, Hagrid's Hut is off in the grounds relatively close to the Forbidden Forest, so since they already made it, they would have to place the Forbidden Forest near that, and it wouldn't... fit... So the layout might be a little... Off... But yes, if they could do it, that would be cool too... I think a guide, such as a wizard (like the ones they have working the que for FJ) would work, because honestly, the Forbidden Forest is dangerous for someone, especially without a guide, so you would have to have someone showing you the animals to make it make sense (plus, it's a wild forest, so they would have to make it look "natural"... With the right line workers, and placement of animatronics, I think your idea would work out well)...