I think the bridge from the Loch Ness Monster to Rhinefield / Land of Dragons should be open. They could decorate the stairs leading down from the Loch Ness Monster, decorate the bridge on the Rhine River, put some decorations in the River, decorate the boat docks, and decorate the path / hill leading up to the Land of Dragons. Not to mention, it would give another path through the park and ease some congestion in Ireland and by Pompeii.
As has been said the reason the park his this area closed is that it frequently gets iced over and is unsafe.
Actually almost all of the lights in the park are powered by generators not just some of them. The park rents something like 30 large industrial trailer generators and places then all over the park.You have to consider available power. Many of the trees along the track in "unoccupied" areas such as near Boneyard Road are powered by generators. They have to have access to refuel as well as start/stop.
Once Pantheon opens, you'll have limited access areas on both sides of the river. Might be a safety issue for personnel to access the coaster areas as well.