Entertainment events at the resorts are only annouced month-by-month, so it's hard to say, but I'm sure there will be some fun goings on. See the Recreation Activities Schedules
page and check out last year's events.
The Not-So-Scary Halloween parties are GREAT fun by the way, and well worth doing once at least, but the one on 31st October will be packed so I'd suggest you look for a different date if you can. Don't tag it onto a park day as the kids will get quite tired, but arrive at the MK at the earliest admission time (usually 4pm) to get the best value from the ticket.