I don't think engagement photos are generally about publicity.
I don't even know what you mean LOL
The viewers are the couple. If they just want some nice photos together then it doesn't matter whether or not we see a story in the images.
I feel like there's this push to put every photo in the context of what would look good on social media.
The viewers are the couple, the friends, the families, whoever they're going to share that with (either online or offline), whoever the friends/families are going to share the photos with, and if you want to do this as a business then your potential clients. The couple will always LOVE their own photos, but other people may not. This has nothing to do with social media. Photographs that tell amazing stories have been around before the Internet.
There's always a story to each image. If there isn't, there should be when it comes to engagement and wedding photography. The "story" more or less about the emotional connection, the interaction, the feel that you get when you look at this type of photos (even if it's your own). I mean if you want a few nice photos then full auto mode, golden hour, snap snap. You get some nice photos. If you want photos that will generate some sort of emotion, it's a whole different "story".