I wouldn't worry too much about this. That message isn't saying "we don't expect to ship until after Dec 25" as much as it is saying "We don't have the ability to assure delivery in time for Christmas" -- possibly just because they don't actually have it in their hands yet. It's likely just a boolean flag in their database for all products -- "can deliver by xmas Y/N" and they historically don't flip that flag to Y unless they have product in stock and really are sure they can get it out in time.