Adventure Awaits Invisible?

If you use mods/cc,try moving the whole mods folder to another place, delete the localthumbcache.package and then test to see if the issue remains without mods/cc there.
If the issue remains, try resetting your sims 4 folder, and testing in a new save game without putting back any of your data in the sims 4 folder and see if the world appears then.
https://sims4.crinrict.com/eng/2014/09/resetting-the-game-to-factory-settings-without-reinstalling/

I did all that and when I launched a new game, it only showed the worlds I did have, it completely took away all the ones I didn't have, which wasn't like this before. 

Do you own the Adventure Awaits pack?

No, but it should at least still show up on the list of worlds that I also don't have. I don't want to buy the pack unless I can at least physically see the new world on the list. All other packs that I do not own show up with no problem, with mods installed or not. 

I hope this isn't a big issue and maybe just something related to the last update, but whenever I go into build/buy or CaS and apply the pack filters, the latest pack doesn't show up. Now, I don't own it (yet), but usually, unowned packs still appear in the list but are greyed out. This one doesn't, and when I go to manage world, there's no greyed out world icon either (see screenshot).

I verified the files via Steam and emptied the cache on the EA app, but that didn't seem to do the trick. I don't use any mods or CC. Any advice on what else I could try? I'm a bit worried about my save... I've started it over 2,5 years ago and I'm kinda attached to all the Sims I've created since then.

It's seems a bit on and off if they show or not. If you don't have the pack I wouldn't worry about it.

Thanks :) I'm a bit paranoid re. save corruption because that save is huge (almost 40 MB even though I deleted some builds I don't need); I guess I'll upload all my households and their homes to my library/gallery in case something bad happens, haven't done that in a while anyway.