"You can't tell me that you're not at least curious to see how all this works out."

Because somehow, Matt's become the person who knows Rebekah the best outside of Elijah, in all likelihood. And unlike her older brother, Matt's more willing to see the changes in Rebekah, to see her as she is now versus how she used to be. He doesn't have a thousand years of history to inform him of how she supposedly ought to be, just the here and now and that summer they spent together abroad.