Its going to be a small indie game......very very few will go out of their way to buy a console for such a small game. Willing to bet people dont even know Rare isnt the one making it.......and that Dlala is the main dev. Granted no one knows who Dlala is lol
I don't even know what Battletoads is without looking it up on Google. Banjo Kazooie or Perfect Dark, sure, but I never heard of Battletoads before Spencer used it on a T shirt. And even if I'm not a very old gamer and don't know a lot of the pre-PS1 era, I'm certain that I know more than the average customer.
So no, I don't think the game will be big, and even less a system seller, especially if they want to sell it with the name alone. You can sell Crash or Spyro on nostalgia, not Battletoads IMO. So it can release anytime they want, it won't change a thing.