It would seem so. Nintendo of Europe recently added images of Gameboy Advance games to their press site within a section meant for screenshots for new games. The games added : Super Mario Ball, Mario Golf Advance Tour and Mario & Luigi Superstar Saga.
There will be a Nintendo Direct this Thursday in Europe, it could well shed some light on this with an official announcement.
3DS Ambassadors currently own the following GBA titles:
F-Zero Maximum Velocity, Super Mario Advance 3: Yoshi’s Island, The Legend of Zelda: The Minish Cap, Fire Emblem: The Sacred Stones, Kirby & the Amazing Mirror, Mario Kart: Super Circuit, Mario vs. Donkey Kong, Metroid Fusion, Wario Land 4 and WarioWare Inc: Mega Microgames.
I'd expect these very titles will appear on the eShop service also.