If you're a UK PS4 owner, the PSN store currently shows the icon for an HD console port of Final Fantasy XV Pocket Edition. Which is certainly something of a surprise, not least because a store icon suggests this is very close to release.
To check for yourself go to 'Games', then to 'New', and (as at the time of writing) you'll see the icon for Final Fantasy XV Pocket Edition HD as above. If you click on the icon, you'll get a message saying "This content cannot be selected at this time."
Final Fantasy XV Pocket Edition HD does not appear on any other regional PS4 PSN stores, and doesn't appear on the UK browser-based version of the store, but that icon definitely got onto peoples' PS4s somehow.
At Gamescom back in 2017, there was a lot of discussion of Final Fantasy XV coming to Nintendo Switch in some form in the future, and a wider console port of Pocket Edition would certainly make some kind of sense in that context