
Samsung accounts made before May 31 are not affected
It's worth noting that the new free storage bandwidth doesn't go into effect immediately and won't affect those who have made a Samsung account before May 31. That means there's still a week left for those who create a new Samsung account to get 15GB of storage. Not that having all that storage is that useful, as it is easy to run out quickly if you enable sync for images and videos. In fact, gallery sync comes enabled by default when you login to a Samsung account on a Galaxy device, so the 15GB of storage doesn't take time to fill up.
The 5GB of storage should be enough for most users once they disable image and video backup on their device (you can do this from the Settings » Accounts and Backup » Samsung Cloud menu); it's perhaps a good idea to disable app backup as well, as Google already knows what apps one has installed on an Android device with a Google account logged in. Since Google restores those apps from the Play Store (unlike Samsung, which saves the installation files on its own servers), there's the added benefit of getting the latest version of the apps when you restore them on a new device.
Thanks for the tip, PJAYA!