Zorri doesn’t really serve any other purpose. She’s another “find the thing to find the thing” in the chain. She helps them find Babu Frik, who Poe theoretically already knows how to find (being that he got to the right town on the right planet and Babu’s workshop ain’t new). She also has the contrived medallion that the heroes have never needed to sneak aboard a ship before.
She’s used to reveal backstory for Poe, but it’s unnecessary. It doesn’t reveal secrets that make us or the other characters question anything we know about who he is now, or question if the characters can trust him. It’s thrown in as a joke that kinda contradicts the rest of the history we know of him.
She’s there for him to have a female love interest. The rest is added on so they can skip developing it. It’s also hamfisted to show his interest in her, and she doesn’t even return the interest.
It’s designed to make it clear in no uncertain terms that the characters the fans and cast have desired to be gay isn’t, and it was done to make sure the film could open well in China (Where Star Wars doesn’t make money anyway). They could have just not wedged an extra romance into an overstuffed movie, not confirming any romantic interest from the character. Instead they teased that there would be representation, knowing that people would interpret that as Poe (even without a romance with Finn), and then made it a background shot.
Abrams said he wanted LGBTQ+ people to see themselves in the movie, seeing myself as an unnamed backdrop that’s unable to share any time with my romantic interest besides a pandering kiss in the background of a wide shot is pretty insulting. He’s the one that made a decision out of spite, I simplified story threads that went nowhere (Rey & Finn Romance), cut a silly and tacked on relationship (Poe & Zorri), and further developed a relationship that was built in all three films (Finn & Poe).