I think they said when they launched it that it wasn't going to be a limited time celebration (a la 25th celebration for 15 months) but rather, would be a new set of services for group travelers that would continue after the introductory period is over. So I'm thinking while they may stop advertising "Magical Gatherings" next year sometime, the Grand Gatherings program will continue.... Sure do hope so, as our family did one in December but since they're not nuts like me, it will be a bit before I can talk them into going back
No. It's the new fireworks at Magic Kingdom, and as such, will probably be there for years...like Fantasy in the Sky was. They just don't change the finales very often...You should have plenty of time to see it....