Originally Posted by
love_flying_hate_strikes
Just so I understand - can I therefore trust what MMB says the aircraft will be? Do they plan aircraft moves very far in advance?
Usually, but not always.
The seat map for your specific flight will always be the best indicator of what is the current planned aircraft. For years, I've not trusted the MMB aircraft type indication in the header above the seat map because there was a bug that made that sticky even though the aircraft type had actually changed - I don't know whether that's been fixed.
If you are really concerned about this, you may be better off using a paid service like ExpertFlyer to alert you to any aircraft type or configuration changes.