You joke but I'm sure if it was invented or brought to Europe now, they wouldn't be permitted to call it butter, most likely. I would vote peanut paste, alliteration is always cool. Also in my country it's more often labeled as 'peanut cream' ('crema', meaning an emulsion with the consistency/texture of cream, not literal milk cream, that would be 'nata').

But it's quite different, companies wanting to label these drinks as milk are doing so with the intent of confuse people into thinking they have similar nutritional qualities to milk, which is deceitful.