Board Thread:News and Announcements/@comment-807326-20150413110105/@comment-24034641-20150519100646

Fearless Diva wrote: CBS owns roughly 50% of The CW and WB the other half. So Titans on TNT(a sister network of WB) and Supergirl have a better chance of being connected to the Arrowverse than say Gotham or Constantine. This is due to the fact that CBS was the owner of UPN and upon merging with WB, the two became partners. It's why most of their shows say CBS productions when the credits role. While yes, the likelihood of them connecting it is small right now in season 1.... I wouldn't go as far to say as never. There's always a possibilty, albeit a small one. Which can increase if Supergirl begins to struggle in the ratings(which probably won't, but there's a small chance it could since CBS tends to skew older in their demos).

Wikipedia isn't a valuable source, I never use that for any source seeing like on Wikia's, it's edited by the public, however even then, the CW can still strictly say no, also I did say most likely never happen, not outright say that it would never happen. Just going by reviews, and even though Kreisberg wants them to become a similar Universe, they're constantly saying the chances of it happening are next to none.
 * http://en.wikipedia.org/wiki/The_CW