"We understand that these four titles are a small selection of the launch titles for the next-generation Xbox."
You see that quote?
Also, you appear to have missed the part of the rumor "leak" that says the system reveal was delayed due to "specification updates" since the last leak.
We'll obviously because I quoted it to you after reading it. I didn't miss that part and most of those titles will be third party games also on PS4. As for specification changes, it's entirely possible that they were actually changing 'must be online to play games' since we got a huge amount of 'unless this has been changed in the 11th hour' qualifiers from recent leaks confirming online required to play games. They certainly don't have time for huge hardware revisions unless they want to launch much later and we've heard nothing to that affect.
So my point stands?