http://nintendonews.com/2015/08/splatoon-lego-set-proposal-idea/

Pretty nice idea. Expect for small details and ink tanks on the backs of the inklings I'd say they got it down.

I suspect the fanbase of Splatoon is older in general, too old for legos.

The same could be said about Lego, which has a wide periphery demographic just like Splatoon does

I'll have to take your word for it, I have little clue about legos.

Never too old for Legos. In our office, one of the devs brought in a massive bag of Legos and now his desk is like an exhibit for all the wacky things the rest of us came up with.

LEGO already have had several themes that would  be considered adult such as the Lord of the Rings, the Hobit, and Twilight. On top of that Mega Blocks already has a Mario Kart and Halo theme.

Being able to securely fasten characters into a discrete grid system is the exact opposite of being able to move seamlessly through an environment.
Therefore: No!

Like I said, I don't know much about legos.

Twilight legos?

I don't really care for LEGO anymore, but I still think that's pretty damn cool!

Twilight as in the movie series.