Yoshi and the Mysterious Book will sell for $60 in the eShop and will have an MSRP of $70 for the physical cartridge.
An opmist would say that it is $70 game and they are adding a $10 discount for buying it digitally. A pessimist would say that it is a $60 game and there is a $10 fee for the plastic cartridge.


The cartridge will just have a game key on it*, And you still need to download and install it on your system and have Nintendo’s permission to use your switch 2.
(*probably)
According to the box photo on the GameStop site, it does not say that it is a key card.
Nintendo has said that, for now, all first party games are games on cart, though not for games that Nintendo is only the publisher/distributor for (see Pokopia).
Not sure why you are getting down voted when Nintendo told people they will do this for some games.