According to Nintendo's Nintendo Direct, Namco Museum is coming to the Switch eShop. No mention of a retail version was made. This makes things confusing when you go over to the listing for the game on Nintendo.com, which includes the boxart you see above. Boxart for a digital-only title? Seems like something is up here.
It's also worth noting that the official press release for the game doesn't state anything about eShop or retail either way. It just says the game is coming to the Switch.