Overall I don't think it's very likely, as other before have pointed out Xbox is MS's only "cool" brand and I think that does count for something. Also you brought something else up, I think the integration with windows 10 as a service could be far more "defining" than any holiday, although I think if MS wants 3rd parties to keep think it's a no brainier to port to the one they can't stay behind 2-1 like they could be right now. It's not enough to even just "win" the US, I think they really need to get a few more countries on their side because those are the massively growing markets.
You are making a really good point. The way MS treated non-english speaking countries at launch was just embarrassing. Germany and France are big enough, so we got a half-assed localization and meaningless local apps at launch. I still have my X1 set to english because Kinect works waay better than German, even though I have an accent.
TV integration was only available in the UK.
Little countries like Holland were called Tier-2 by MS and didn't get the X1 until later. OK a country like Holland only has around 20 million people, but they are still proud countries who have their own language and don't want to be insulted.
So here in Germany (biggest EU economy) MS lost 1:4 to Sony in sales and it doesn't seem to get better. The only reason I bought the X1 is because I have many US friends on Xbox, ever since I spent a year in Arkansas as an exchange student.
MS got lucky with me, because I use the X1 (combined with a VPN and DirectTV login of a US friend) to watch my Dallas Cowboys and Razorbacks via those apps. But all my friends have PS4's because nobody cares about NFL deals, ESPN or SlingBox.
Brady and Romo could walk into a restaurant over here and would not be recognized.
Only soccer is important in the EU, and Sony has been sponsoring the ChampionsLeague since PSX days.
As far as these holiday titles go, I think people will like them and think "whoa it's a cool game" but they won't spend 350 on an X1 just to play them.