Well it's brought up a lot, but look at Edgar Wright with Ant-Man. He wanted to make an Ant-Man movie for Marvel since before the MCU was even a thing. Once it became the only option to make an non-X-Men/Spider-Man without tying it into everything else, he stuck with it for a while, but only up until they began to force things like Falcon and Agent Carter cameos on him with rewrites behind his back and he started to feel like he wasn't the one directing the movie anymore. Sure there were likely other reasons, but there's no doubt that if Marvel Studios had an option for filmmakers to do work that doesn't need to shoehorn threads for an Avengers movie down the line due to a creative force other than their own, then they'll be more likely to take meetings.Quoting number8 (view post)
Not that they need to right now. DC does.