Totally random thought, but I'm leaning more and more into CP-0 being here mainly to explain and end Big Mom's story. Aka, zero relevance in Elbaf.
So most people know about the whole thing that the long arm and gas mask CP-0 members seem like the 2 children Big Mom terrorized. Was reading her flashback and realized that every single "child" in this double spread might be alive.
Hadjrudin and the female Giant are part of Luffys crew, and the kid giant watching Hadjrudin train is the same one from Sabaody. Coincidentally, the 2 non-giant children are the exact 2 that people keep pointing out to have a resemblance to those CP-0 members.
So my point is, Oda made it seem like there were only 2 witnesses that saw BM eat Caramel and the kids, but what if somehow these 2 escaped? Caramel is also seen negotiating with CP-0 over selling Linlin to them. Maybe they came to pick her up and instead found these 2 terrified, hiding?
Point in getting to is, both of those members are here now, and if they are those kids, they can neatly tidy up Linlin's whole past and close her arc. They could be the only 2 that survived, and can finally explain to her what happened.
With this, Oda could close Big Mom's arc without her ever being relevant to Elbaf. Just something to think about. I do wonder if this is an interaction that could be had if she loses here. May even reform her character in a way.
As much as I hate to say it, BM is much more relevant to Elbaf in general. There's also her past, from before 5 years of age that I think will be explored. Her parents were normal-sized but she's half-giant. She was probably experimented upon by the WG too (based on her love for candy which the experimented kids from Punk Hazard also want too).
The entire Elbaf extremely hates Linlin and there's also her plot with the broken marriage alliance with Loki. We may learn the cause of her giant size and this may connect us to Vegapunk.