Some interesting points here:
Whales are gonna be extremely important by EOS for OP story and world, not just because of the world flooding but that too ofc. Jinbei got whale sharks to help him and everyone else after Impel Down to Marineford too?
With Jinbei the whale shark fishman and Brooks history with Laboon and the SHs meeting Laboon and thus Crocus of the Roger Pirates, I feel whales are gonna play an immense role later on at some point.
Not to mention Whitebeard's ship was a whale in design and called Moby Dick like the legendary whale from the story of the same name.
I had a headcanon that part of the necessities to find Laugh Tale and reach it will require the help of whales, possibly Laboons own pod/herd/school or w/e lol.
Oh how interesting too....
The mural has a whale on it too:
And Franky was the one who witnessed it and we just got a glimpse of him staring at it in awe, what could that lead to? Could Pluton be whale related/themed too?
Another interesting and relevant post too:
https://www.reddit.com/r/OnePiece/comments/vz655u