[SPOILERS] Emeralds Stairs map ending

[MaSeKind]

Keeping this super vague, but if you know you know.

Sooo, does anyone know if the thing happening at the end of the 2nd map always happens?
I assumed it being a pretty big deal that it's just part of the story, but dialogue in the 3rd map now made me question that assumption.

I forgot something I wanted to do before the main quest part towards the end and know it's related to that big event, but don't have a save to replay it all again now to check.

I stumbled upon this place earlier and then realised I should maybe not be here yet, mainly because of the enemy levels, and I went there after the main quest event and read the notes so it's definitely related. It's also different after the main quest.

I'm just curious if going there before actually impacts the story. That would be some awesome decision/consequence stuff, and definitely what I would expect from this game.