Salmonid siblings Lee and Kami are here to give an important SOS (SaveOurSalmons) message :O Since Nintendo made that post in new year, I can't stop thinking that maybe this is gonna be the plot for Splatoon 3 and it's really interesting!
I imagine the case where salmonids find themselves under a bigger threat they can't beat, so they have to go to their old rivals, inkling and octoling, to ask for help. Maybe Marina notices this before others, so she goes to help but never comes back, then agents 4 and 8 (the player - I don't wanna be a new agent again, lol!), together with 3, Pearl, the Cap'n and the Squidsisters embarc on an adventure to save Marina and the Salmonids!!
I think a plot like this one would be great; a new style for the stages, challenges and story for the hero mode!! Besides, this will refresh the series, giving us a new reason to fight out of the Zapfish and Dj Octavio (and having the salmonids as friends would be cute, don't you think?)