You're welcome. When I first learned about the rabbit island, I didn't know about its dark past, either. Learning about it just made the island that more special. There are great videos of people enjoying the bunnies on youtube, but some had some cursing, so I didn't post it. There's a good travelogue by a Polish couple (their English is very good) and they talk about the hotel there.
There aren't any cars there, either. But some workers have little jeeps and they go around making sure the rabbits have water. So they are safe from traffic, too.
They are some happy rabbits. I think you are right, they may have descended from lab rabbits. If so, that makes the story even better. IF I ever get to Japan, I want to go to rabbit island.