Yes note the marketing reference
it's more a play on words, non duplicative vs deduplication.
The snaps are non duplicative in that the de-duplication of data is across snaps within a tree not within the snapshot data itself. So if we have 30 snaps sharing a single block and that block is overwritten then a single block is written to Snapshot Data space and Snapshot Admin space is updated with pointers for the 30 snaps pointing to the new location. On some older systems this would result in 30+ backend writes. If we then overwrite another shared block with identical data to the above, then another block will be written to SD space and SA space modified accordingly.
So no de-duplication within the Snapshot Data space, but across the snapshot tree via Snapshot Admin space.