The leaked OFLC ratings for Mega Man Battle Network 3 Blue and White are indeed true. Speaking with IGN, a Capcom spokesperson has confirmed both versions for Wii U. What's more, it appears additional GBA games from Capcom are in the pipeline. Here's the quote:
"We are working on bringing this and other GBA titles to the North American Virtual Console," a Capcom spokesperson said. "We'll have more information about the lineup in the coming months. For Australia and Europe, we are still in discussions about the release of Virtual Console titles for those markets."
The company's GBA library is bursting with Mega Man games, as you'll recall. I've little doubt we won't see all twelve on Wii U eventually. Naturally, we'll keep an ear out for future updates.