With all the acquisitions happening at Microsoft and the changing lineup for future releases, we've put together a full list of all upcoming Xbox exclusives.
I believe most of the third party games in the list would be timed exclusive at best, and some have just not announced other platforms yet, but may launch on other platforms as well, but even with just Xbox Game Studios games, that's quite a list.
Hope MS can manage them well, and produce high quality games.
Yeah, both are possible. But unless someone officially claims some exclusivity, I am just going to ignore it. It's very common to have a trailer on one platform without mentioning anything else, but then releasing on other platforms too.