As the new model uses MTP to communicate with the computer, there is no need to partition the userstore
merely to prevent people copying their B&N content off the device.
Perhaps that is what changed.
...
MTP is fundamentally different from USBMS, in that the device has control over which files the PC host sees -- as opposed to being forced to display the entire block device (at which point the PC is free to access whichever files it likes).
B&N may have instructed the Glowlight Plus to only share a "sideloaded content" directory.
This is better than before, when the Nook "protected" B&N books by keeping them on a separate partition. At least now you can use as much storage for sideloaded books as you like.
But it certainly doesn't mean you are going to be allowed to access your own purchased B&N content!
Yeah, B&N sure knows what they are doing.
Make a device that is most useful for people who DON'T buy ebooks from B&N.