This would be awesome, because at the moment this still feels a bit like a themepark MMO. I always know where to get a steppe horse, or where to farm bush pigs.
It would be cool to further that into animal migration based on the season. Don't know if they will implement some type of season mechanic but having animals move from one area to another over time would be cool, might melt the servers but would be cool.
I would love to be traveling between towns and get bounced by a pack of wolves or a bear out of nowhere. As it is now I can avoid mobs all together cause I know where they will be and their leash range.