From what I can also tell, the Royal Edition changes seem to specifically stop (in terms of cutscenes or "new" events") after you get out of the elevator (after the kings i guess) in the citadel and confront Ardyn (I can't find any changes after that, but it is possible still). So for those of you that want a quick summary on most of the important changes made to Insomnia, here:
- Bigger Map (Fast Travel Points and a new Regalia)
- An expansive underground (You need keys to unlock parts of it to new areas of the city)
- At least 4 new side quests (I think there are more)
- Cor is a guest party member
- Your Comrades Glaive is a guest party member
- It seems you take on the King Behemoth with your Comrades Glaive (It's not an objective, but there is code there labeled AVATAR_KG_BHM or something like that)
- Luna is assumed to be a guest party member (has similar code like the above for it) for a least one event
- Cor may be a boss fight (but don't quote me on this yet). I also don't know where it would happen (but it looks like around the Cerberus fight)
- Cerberus is a two stage fight
- Ifrit may have additions to his fight. There seem to be some sort of changes happening ( I personally think they are adding the new additions from the fight in the Comrades update)
- The Kings come after Ifrit (obviously) and the 3rd King is a 2 stage fight.
- Ardyn doesn't change from what I'm seeing (There may be additions to his dialogue though, not sure)
- Two awesome story portions/events I'm not talking about
Take the above with partial skepticism. I also can't be sure Ardyn doesn't change because I specifically can't even find a battle/event for Omega, which we all know is there.
2 More things:
1. Bonus for those who care about comrades, the new Ifrit/Ardyn event should be taking place after Angelgard:
"After months of searching, the Glaives successfully recover the once-lost royal vessel and restore it to ship shape. Despite having finally provided access to the Umbral Isle of Angelgard, however, their work is not yet finished. The engineers at EXINERIS have asked the Glaives to assist them with their next project: the completion of their cross-continental electric grid, culminating in the restoration of power to the Crown City"
Your new goal in comrades after is to actually restore power to Hammerhead and Insomnia, this is probably why the event with Ifrit and Ardyn happens in the trailer. You also restore power to Caem for the new chocobo stuff, and I think you use them to find the rest of the royal sigils (this I'm not too sure about)
2. Another thing, if someone wants to correct me and tell me if they've seen this text before:
"Reunited at long last, Noctis and his brothers-in-arms set forth from Hammerhead with their sights on the Crown City. Though little distance separates the friends from their destination, their trek is nevertheless fraught with danger. Undeterred by a world drenched in darkness and teeming with daemons, they push bravely on toward the hill overlooking their home".
I'm pretty sure we never get text like this on a loading screen or anywhere else. I know for a fact that within the Datalog, there seems to be a story recap section as well. This is probably part of it, but one thing sticks out here: It talks about leaving hammerhead and heading to the campsite as if you actually play that part now. Now, even if that happens, it doesn't confirm you get to travel directly to insomnia after this. I'll update if I can find more dialogue on it.