Final Fantasy XV was supposed to be getting four more DLC episodes, but only one of the upcoming four will now be released. The rest are cancelled, while the game's director Hajime Tabata has resigned from Square Enix entirely.
As explained by global brand director Akio Ofuji in the video above, only the Episode Ardyn of the "Dawn of the Future" series will launch, in 2019. The rest of the DLC has been scrapped. The game's director Hajime Tabata has resigned at the same time as this announcement, both from Square Enix and Luminous Collective. Luminous was set up this year to work on a brand new AAA title with Tabata attached, but it appears they will be moving in a new direction without him.
"Episode Ardyn" will release in March 2019, presumably the last major update for Final Fantasy XV.