I don’t suppose anyone knows when November/December hours will be officially posted? I have an idea but would love to confirm. Thanks 
From what I have observed, Disney post official hours a bit more than six months prior (so, mid-Mayish for Nov hours). However, they also update those official hours closer to the actual time. For example, for my June 2015 trip, Disney modified the hours in May, by moving the official park opening at MK back to 8am instead of 9am (this sticks in my mind because my 8:05 crystal palace breakfast was no longer so helpful for getting us in the park early :/). And I even recall there being a couple of last-minute changes to the hours and schedule during a Thanksgiving trip one year.
Thank you! I thought it would be late spring/early summer. Do you think this is also when MVMCP tickets will go on sale? I see the dates are published for that, so obviously we know what nights MK closes at 7:00, but not available to buy yet.
They should be on sale soon. You should not have any trouble getting tickets for that time of the season.
Actually, the initial November hours have been released for a couple of weeks now - see the TA calendar at http://media.disneywebcontent.com/StaticFiles/ParkHours/WDWTravelAgent_november.pdf
December hours should be posed mid-May at http://media.disneywebcontent.com/StaticFiles/ParkHours/WDWTravelAgent_December.pdf. Currently it has Dec 2015, but that will change once they load the new PDF. In fact, you can see the TA calendar for any month - just use the link above and change the month name at the end of it.
The problem with the calendars is that we all know it will change. HS has not listed any fireworks and AK is scheduled to close at 5:00 for most of the summer on. It is so hard to plan when you know there will be so many changes!