I think the mermaid fence was part of your home decor. So you went to Nook to do customs to your house and mermaid theme was one of them. So you could choose door, fence, roof, ect. I'm still trying to get most of pirate Gulliver's stuff. He's given me most of the clothes for the pirate costume, so I hope he can actually give me the pirate theme stuff now.I didn't gloss over your post. I read it several times before deciding to respond. I even reread it just now. I will admit to still being a bit sleepy from a nap, so it is totally possible that I missed that one line several times. (Because I just reread it again and saw it. I'm only human. Sometimes I wish I was Ribbot.)
I would also like to point out that all of the holiday items have technically been redesigned. So technically, they are new. And customizable! The way you get the pirate items is also new in this game and the way you get the mermaid items in this game are new. They even put in the mermaid fence which is brand new. (I think? Was there a mermaid fence for your house in NL? I honestly forget) There are variations of megaphonesnow where there was only one before. We have got new reactions and new hairstyles that weren't in any AC game before. This is the first game where we can all get regional items easily (even if they are just something to be ordered from the catalog).
They just might not be totally revamping how each holiday works or making something new in that respect. But to say that they haven't been adding new things in the updates is untrue.
Pascal used to give the pirate stuff and the mermaid stuff was part of Club Toritmers mini-game rewards. It took a lot of medals to buy the sets. So even though Pascal can be a pain in the butt of giving you pearls instead of diy, it's not as time consuming. Or it may be the same amount depending on how lucky you get. Because you still do need to catch the pearls to craft.
I remember spending a full day doing medals and then jumping club islands to buy the full set for one of my friend's birthdays. They kind of stopped being my friend soon after lol, so I should had kept it for myself.
Also that was my fault. I wrote content and I meant updates. That is on me, I am an idiot lol.