It doesn't appear that the support was included in the Sprint update. Sprint would have to update their own drivers to interface with the new API for RAW in Lollipop.
And Samsung will abandon the Note4 long before that as well. I wouldn't be surprised at all if this is the last Android version update we get. Maybe a few carrier specific ones to fix bugs and add bloatware but nothing from Samsung itself.7.0 will be out before that happens.
One of the biggest features enabled by the new Camera API in Lollipop is support for raw image formats. Raw images are the closest thing we get to the full, uncompressed information output by a camera sensor. The typical JPEG file, in contrast, contains just a small portion of that information, in order to minimize file size.
I guess you can't believe anything you read.
Here’s what Lollipop’s raw image support can do for the Nexus 5 camera