Yes, Asobo is going to be off the end of December. Regardless what people may think, they have pushed really hard all year long, and had to forego vacations in the summer, etc. They need their time off. So they are looking to resolve the big items, the ones that are most disruptive, to get MSFS in the most solid state for the holidays, so customers can enjoy the holidays and the Asobo folks can enjoy their time off. So yes, this hotfix will go out before the holidays.
One rather interesting thing though is, while Asobo is off for the holidays, I wonder how 3rd party updates are going to be handled. There are still developers having to make and submit changes due to SU7 breaking their mod. With no one to process those during the holidays, I wonder how that is going to work (Maybe they have already planned that and Microsoft employees in Seattle will be doing testing, DRM management, and then placing into the marketplace while Asobo is off.)