Recently returned to the game after a ten year absence, about half my current games are continuing from saves dated summer 2016. All is well except for some weirdness (I mentioned missing aquariums in another thread, but these new oddities aren't about items).

Suddenly all my sims with cars have those cars on their friend list. I thought this was a feature of the Fast Lanes SP, which I do not have. I just downloaded a mod to remove this.

I continually get messages (upper right of screen) along the lines of, "Great job! Those vampires and zombies will think twice before returning." This sounds like something from Supernatural EP, which I also do not have. I can ignore this, it's just curious. (With NRAAS I have disabled all mention of occult careers, immigrants, etc.)

I have three characters in Sunlit Tides (different games/saves). On one of them, a continuation of a 2016 game, almost all the ladies in town now have the career "Papparazzi Mama". What the....?! I've never seen this anywhere else and no idea from where it came. Other than bailing this game (NO!) or painstakingly editing each sim back to their original career, is there a simple solution to this?

My original game only had Ambitions and Seasons, my new install added Generations to this; could it be the cause of these anomalies?

Sims with trait vehicle enthusiast can have cars, etc in friends list. Not sure if that's only with Fast Lane. Vampires are also in Late Night, if you have that, but pretty sure zombies are only SN, so no idea what that could be.

Are you also playing with the same mods you had ten years ago? They would be terribly out of date by now, if so.
Is the game itself up to date?

Aside from the car friendships, none of what you mentioned sounds recognisable from the unmodded game. That career title especially is definitely not EA.
Exact quotes or screenshots of the notifications would be helpful to identify.

You may have some very old mod content in play, or perhaps some large / intrusive mods doing things with townies.

Game version 1.67, same as I had back then. I found a backup of my "Documents.....Sims3" folder on an old HD, reinstalled the game on my new system, checked it, then copied that old backup to new system and started playing; revisiting my old saves (what a time warp) and starting several new games.

Attached, hopefully, is my packages list

Three of the first four ladies on this character's friend list in Sunlit Tides have this career...

The package list was very helpful, as it includes the date of the files

Your NRaas mods are from 2014 (12 years outdated!) so you'll probably see a lot of old weirdness that we don't even have documentation about anymore :P
I'd definitely recommend deleting those and downloading fresh copies - just note that the website is in the process of a server move, so if any downloads aren't working give it a couple of hours and try again.
Your settings will be preserved, at least the ones that still exist in the current versions.

Apparently 'Mama/Papa Paparazzi' is the first career level of the self-employed Photographer career. Not as weird as I first thought, but something is causing these sims to be reassigned to that career.
After updating, give them new careers with MasterController and see if the issue returns.

I can't spot any other notable script mods in the list, but you can also try removing the other files if strange behaviour continues.