Honestly, I wouldn't expect either to be able to provide much information. What they've already "published" is likely to be all we see for quite some time. This is a big, long term project and I'm sure they'll want the flexibility to move various parts of the project around on their timeline without having told anyone the original timeline.
I am pretty sure that MS would not be able to tell you anything about this. You can try calling Guest Services but again, I wouldn't hold out much hope for real information.
Personally I would go ahead with your plans, ask for an even number room (bus side) near the elevators. I think the Lodge will still have that awesome Christmas decoration and feel that we all love so much. The key for this type of thing is the mindset...if you are upset/bummed before you get there it seems likely to run over into the vacation time.
I feel for you, but at this point I'd try to keep the hope that Disney will deliver a Christmas experience you will cherish for years to come. Good luck!