Super Mario Advance 4: Super Mario Brothers 3 has been announced for Japan.
Not only does this complete the lineup of classic ports from the GBA for this franchise on the Wii U while providing a way to experience the fine SuperNes remastering of SMB3 on the Wii U directly, but the best part of it all is that it seems to include the e-Reader content.
https://www.nintendo.co.jp/titles/20010000008346
I'd of never bet on seeing that material be accessible here when this finally made its way to the Wii U.