After 2 INK-credible years of Splatoon 3, regular updates will come to a close. Don't worry! Splatoween, Frosty Fest, Spring Fest, and Summer Nights will continue with some returning themes!
Updates for weapon adjustments will be released as needed.
Big Run, Eggstra Work, and Monthly Challenges will continue for the time being.
Also they just released a video celebrating each splat-fest: https://www.youtube.com/watch?v=cd3qYJRnI7E
Large parts? It's been a while since I played Octo Canyon, but I'm pretty sure the only thing that reappeared from Valley was the Octostomp boss, but it's a different fight anyway so not really.