There should be some space to the left side of the pavilion to add extended queue if they re-route the backstage delivery entrance to Odyssey - or - on the right side if they eat into the neighboring expansion plot, (or just take over the garden walkway/Donald meet and greet area and re-route wheelchair ramp.)The biggest issue here, as we discussed earlier, is ride capacity and queue management.
They have no room in that pavilion for the queue for the current incarnation of that ride, let alone the Frozen+ size crowds I would expect for Coco.
If they do this, I think they need to consider revamping the inside of the pavilion and maybe an outdoor or annexed queue solution.