Snake has never been important to Nintendo. Nothing's changed since Brawl. In fact, Kojima acknowledges Metal Gear's irrelevance to Nintendo as one of the reasons Snake was put in Brawl in the first place:Both Sonic and Mega Man have had long-term, consistent relationships with Nintendo platforms. Snake has not.
Snake isn't in Smash Bros. because he's a Nintendo all-star; he's in Smash Bros. because he's a video game all-star. If Sakurai was okay with including him in Brawl, I don't see why he'd suddenly be against it now.http://www.joystiq.com/2012/03/19/thank-kojimas-son-for-getting-snake-into-smash-bros-brawl/ said:Aside from his son's pleading, Kojima pointed to Metal Gear's low profile on Nintendo consoles as a second reason.
"As you know, we did make Twin Snakes, but generally speaking, there hasn't been a lot of Metal Gear on Nintendo platforms. So from that perspective, I thought it was a good way to expose younger people to this character, Snake," he said. It must be working, as Snake is one of Brawl's most popular characters.