I suspect this is true. If they made it microSD-sized, it'd be very difficult to change games on the go and would easily get lost in the bottom of a backpack.
You see this on the PS Vita as well: the memory cards, which are meant to be changed rarely if ever, are roughly the size of a microSD card while the game cartridges are probably double the width and height even though the storage capacity of the carts tend to be much less (2-4GB) than the memory cards (8-64 GB).
You see this on the PS Vita as well: the memory cards, which are meant to be changed rarely if ever, are roughly the size of a microSD card while the game cartridges are probably double the width and height even though the storage capacity of the carts tend to be much less (2-4GB) than the memory cards (8-64 GB).