>>122099It adds a few things, most notably there's now a text based dating sim mode where you can chat with lots of characters and choose to romantically pursue one or more - but that's not all it's used for, it's also there to help drop lots of lore, progress plots between story beats, etc. I like it as a system, since it can provide a lot of interesting context without the devs needing to take ages recording voices or modeling 3D scenes. Once you do romantically engage with someone, you get a cute scene about it, and some of them can become NPCs chilling in your home base from then on, but otherwise it's mostly words on a page.
As for where it fits in to the rest of the game, Warframe is a complicated beast - there's a ton of story, it's mostly very good, and it's so good that the fans like to hide spoilers from new players so as not to rob them of the biggest moments - and, like you said, they make no sense out of context anyway.
So, there is absolutely a solid throughway that goes from
"You are a mysterious space ninja from an ancient warrior caste called the Tenno, who does short third person shooter missions to help fight the evils of murder clones and space capitalists."
to
"You are dating multiple superpowered blorbos via magitech time travel because the power of love can save you from Space Cthulhu™."
... It's just not a throughway that can be adequately explained without just playing it.
I started playing ages before the plot got especially wibbly, and to be honest I love what they've done with it, though I was quite hesitant at first. I'm a sucker for emotionally centered storytelling and they're consistently making me cry with these updates.