"Fixed a bug that caused size 2 fish to be catchable"
they basically announced they've given up

Hi!
I was wrong. SO wrong. We're finally getting new size 2 lore tidbits after a full 2 years of waiting. Here's what we got - (SPOILERS BY THE WAY)
THE AGNES GORGE TRAIL
The Agnes Gorge Trail has been found! It's behind 7-S's waterfall and it goes on for miles... although unfortunately right at the end you get trolled by a red skull door. There is allegedly a way to get past it according to a couple friends of mine (if you know what it is, please comment) and what waits on the other side is pretty dissapointing. Sure, there's a beach but all we got was just a note saying "GONE FISHIN! -SIZE 2")

Still, size 2 news are size 2 news. MAYBE we'll be able to find it.

REMEMBER
WE HAVE TO SEE
WE HAVE TO KNOW

I'm starting to doubt that they'll even add it in in the first place.

But for now, stay fishing I suppose.
WE. HAVE TO SEE.
and WE. HAVE TO KNOW.

"Hey psst
the waterfalls conceal the water up's
agnes gorge trail
use your ability and find size 2"

My best guess is that the "waterfalls conceal the water up's" are talking about the fact that there is water sealed up by the waterfall, but unfortunately that can't be the location for size 2 considering that space is already taken by 2 fish.

Offtopic here, but my best guess is that size 2 doesn't exist right NOW, but will be added in a patch eventually silently.
For now, stay fishing!
WE. HAVE TO SEE.
and WE. HAVE TO KNOW.