Those wishing for 64GB Nintendo Switch game cards will have to keep waiting. According to a Wall Street Journal report, Nintendo pushed back the rollout of 64GB game cards until 2019, citing "technical issues" as the problem. Game developers get Switch cards from Nintendo, so this means that they'll have to wait to get game cards that can support big titles.
Currently, Switch devices have 32GB of internal storage; however, it comes out to about 26GB of usable space, as a portion is reserved for system software. Switch game cards currently support 32GB of storage, and they're able to easily hold games like Super Mario Odyssey and The Legend of Zelda: Breath of the Wild.
Nintendo planned to release 64GB game cards in the second half of 2018 to support larger games, but it appears those cards won't be ready for another full year or more. Some big titles require more storage from the get-go, and 32GB simply won't cut it.