Super Metroid is my #2 of all time, and as a huge fan I personally don't think it needs a remake. But I don't think a remake would be a bad thing for 2 reasons:
1.The original is available on the SNES, Switch, SNES Classic, N3DS, Wii, and Wii U. A remake wouldn't undo that and I'll still have my pixel perfect 1994 game.
2. Since it's such a well designed game, adding new HD art style and $60 price tag is fairly safe, easy money for Nintendo.
If Nintendo is wondering if there's a market for 2D Metroid on the Switch, a Super Metroid remake has the best chance of proving that. It's relatively low risk, but if doesn't sell well, then there's not really a market for $60 2D Metroid games.
So in short, if an SM remake keeps the franchise strong, fine. I think that it makes sense for their business, even if I don't think the game needs remaking.