Chris Avellone was asked on Twitter about confirmation on the cut ending Join the Think Tank in Old World Blues. He confirmed what's in the wiki and added the comments:
This just goes to show those that always said that "Bethesda didn't forbid Obsidian from doing anything in FNV!".
Ah damn, that sounds so badass!!! I'm sad Bethesda is so petty they'd restrict an ending slide and some dialogue.