I am guessing that Apple is responsible for DNG decoding, now, rather than Adobe, although Adobe should still be responsible for keeping their website up-to-date, and not have dead-end pages without any explanation.
From what I remember, there were some cameras with lens corrections built-in that Apple refuses to show DNG previews of—the DNG Version was too new, but it wouldn’t hurt to check and see if there is a Apple Camera update in case they have fixed this.