Never before has a Zelda game announced or teased another upcoming Zelda game. They often do contain Easter eggs though.
What makes Majora's Mask remake more likely is not whats in Link Between World, but what became before LBW, when Miyamoto was stuck on deciding if he wanted to do a Majora remake, a LttP remake, or a sequel to LttP. Before ALttp sequel was even officially announced, it was already rumored/teased that it might happen during an interview.
If Aonuma said something like "If you play A Link Between Worlds, you may get an answer. You might find some information." well then that points even more towards a MM remake because its like, why the hell would he ever say that in the 1st place. Its pretty much saying "The answer is in the game" and as far as I know, the game doesn't say no, so the answer is anywhere from neutral to yes, especially considering they've been interested in the remake for years.
Now here's a fun little something to entertain your brain bags...
They are interested to do a MM remake, a LttP remake, and a LttP sequel. Right? Well MM is pretty much a OoT sequel... And LBW is the sequel to LttP, and now they have an Engine for a 3D Zelda and a 2D one that mimics SNES and N64 Zelda games, right? AND OoT3D had an extra Master Quest Mode, which was basically almost 2 games in one cart... and the Original Majora's Mask didn't have a master quest...
What if... WHAT IF... They make a Majora's Mask remake, and instead of making a MM Master Quest, they instead include a LttP remake, so that this 2-n-1 game could compliment the other two Zelda games on 3DS?
Either that or they actually come up with an original idea, I'd be happy with a remake or an original game on 3DS