I personally don't see that as anything more than general conversation with no relation to Katrina, but I also believe she'll be making an appearance at some point (maybe for a halloween event? since more people seem to be interested in the 'occult' during that time of year)
people have also taken screenshots of their villagers mentioning Brewster and coffee, which we know he and the cafe are likely coming based on datamines, and weeks ago people also took pics of their villagers talking about an art gallery - lo and behold we have it now : )
seems like nintendo is sneaking in hints about future updates
I do have a feeling that most, if not all, NPCs will make a comeback in some sort of way. I really hope they do! I'm hoping for the best, but also trying to not get my hopes up too much!
I'm not sure if that's really a Katrina reference since the whole "days like today are just made for x" is a generic fill-in-the-blank dialogue for the normals--the first time I got it one of my normals told me days like today are just made for free pizza! But whether it is or not I'm still really hoping she'll come back. Luck is probably still in the game so we need a way to know what kind of luck we're having, don't we?
I think even they will come back at some point. Not sure how...but, I think Nintendo will shoe-horn them in somehow. Maybe since the daily limit on sending letters to your friends is only two letters per day, they could bring the pelicans in with a patch that changes that to 5 letters per day (unlimited would be even better).