That's really odd then that they would bother connecting it to the main game in anyway instead of just putting it in the main menu under the special items tab. Not saying it's definitely happening but you think that maybe this is them experimenting with integrating DLC content into the main game? Royal Pack was received really positively for it's integration into the game and I'm sure they're aware of the fan demand for more integrated content as well. It's a long shot but it's interesting that the first real story driven piece of content (even if it's irrelevant to FFXV's story) we've gotten since the Royal pack is accessible through the in game world rather than being put under the special items tab.
They add an information menù with an update list, that means that we get a lot of updates in next months probably... Otherwise will be useless.
The 1.26 update is about 3,7 GB, so now I have a new mission: use the glitched save to catch new things in Cartanica... Maybe this 3,7 GB isn't all about the the new content as they had announced, like the past updates, maybe there's hidden stuff.
(why Cartanica? Because they trying to fix this map adding hidden content in last updates, like new roads and building)