We don’t know anything about Iceland or New Orleans, but I can confirm (thanks to a single offhand reference later in the story) that Hawaii did get hit by Behemoth at some point in the probably-somewhat-recent past, though we don’t know the exact date. (Not quite sure where the spoiler line is, sorry if this crosses it.)
I’ve now made clear to Sharks that I would prefer not to know about info from future offhand references in advance. No worries, though, this is a fairly minor one as far as I can tell.
Honestly, though, spoiler or no spoiler, learning right now that Hawaii was indeed hit by what I’m 95% sure is the volcano Endbringer is quite appropriate.