Extremely unlikely; for years Shin'en have built a name for themselves among Nintendo fans as one of the only third party devs who invests in creating technically excellent games on Nintendo hardware. The vast majority of their fanbase is on Wii U/3DS. On PS4 they're just another unknown indie dev.

Not much is known about their relationship with Nintendo so when Shin'en released Nano Assault NEO-X for PS4 it looked very much as they wanted more attention from Kyoto. 

That be cool.

I'm thinking it's more likely that they wanted to test the waters so to speak, to see if PS4 was a viable source of additional income.

I can't see them abandoning their core audience, which is on Nintendo platforms.

I'm going to buy the game regardless of whether or not there's going to be a retail version.

Not only that, they should hire them to make the next f-zero for them. That working out, they should buy them.

At a 10-20$ pricetag for the game at release (the pricerange I've heard a couple of times, dunno if it's the true pricerange), a physical copy might be too expensive to justify physical copies.

What Nintendo should do however would be compilations of eShop titles with a common theme (like a genre or a graphical style) with a price equivalent of roughly 60$. This would both give the Indies much more exposure and help Nintendo getting over droughts on the retail market.

Honestly, I think a lot more of the marquee indies should get retail distribution. Things definitely seem headed that way.

If Teslagrad could get a retail release, so could this.

I'm basing this price assumption on their prior games for Wii/Wii U, including this game's 2011 predecessor, which were all $10 USD I believe.