The delay comes after it was announced that 10 million units of Nintendo Switch have been moved. And once the Switch's included memory is full, you have to upgrade to expensive external microSD memory. The sources said the move has brought "slight disappointment" to some developers, especially USA publishers who often need the larger capacity for their data-heavy games. According to the WSJ, the reason given is technical issues.
According to a journalist called Takashi Mochizuki from the Wall Street Journal. Switch game cards now 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. This can have several repercussions. Nintendo apparently intentionally sought game cards instead of discs for the Switch as part of its effort to make the system more portable, which is one of its defining attributes.
They said the notice disappointed some software makers, especially US -based publishers that often produce data-heavy games.
Switching back to cartridges hasn't just left a mark on the higher price tag of Nintendo's games, but also posed a tough limitation on storage for developers to abide by. That's too small for games such as Doom and Breath of the Wild which also require gigabytes of data be downloaded. And it absolutely must avoid the awful working relationship it had with third-parties in the disastrous Wii U-era.