Yep, that's what I'm referring to. It does seem like there's some dissonance between the strength of that word in the USA and in the UK; I recall being very surprised at its usage in the wonderful children's cartoon Dan Vs., for example. So perhaps it's not as severe as it feels to me.
Treehouse thrives on puns...it seems to be their culture. I'm fairly sure they tried to use every last fish pun they could find everywhere in the game and someone pointed out the obvious one that hadn't been used yet. I'm guessing since the original flavor text half of the staff was going "Bill, Bill, we HAVE to put this one in" ("NO!") "Bill, how about for splatfests, it'll only be seen once?" "(NO!") "C'mon Bill we can't let it go to waste" ("NO!") "It's the last Splatfest, Bill, nobody even plays anymore, can't we put it in now" ("Oh, we're still doing Splatoon text? Fine, whatever. I have to catch a Charizard in that trail near my house I wouldn't stop going on about at E3.")
And we all know Marie finds puns punbearable....
But we already have Callie with "Holy Mackerel!' for Port Mackerel, so that adds some grounded context to have another...err...holy fish... :p