Samsung decided not to use the Android Marshmallow "adoptable storage" model. We believe that our users want a microSD card to transfer files between their phone and other devices (laptop, tablet, etc), especially the photos and videos they shoot with the camera.

With adoptable storage, first of all the card may be erased the first time it is inserted into the device. This behavior may be unexpected by many users and we donﾂ稚 want our users to lose their files. Second, once Marshmallow starts using a card for adoptable storage, it cannot be read by other devices, so it loses this ability to be used for file transfer. Adoptable Storage is also primarily targeted towards emerging markets where devices with only 4-8GB of onboard storage are common. We think that our model of using microSD for mass storage is more in-line with our ownerﾂ痴 desires and expectations for how microSD should behave.