Now let's break down these lists.
There were 66 total games announced for PS4 since 9/1. Of those, 47 had no mention of an XB1 release on the developer's website or social media channels (one of them being first party/Sony published, bringing it down to 46). If we were to take out all Playstation Experience related announcements, if the argument were that those titles would only be announced for PS4 at that time since it was a PS exclusive event (despite the fact that two of those PSX announcements were also announced for XB1),
that still leaves 33 titles with no XB1 release plans announced.