I am pretty sure the idea people are talking about here has nothing to do with messaging and everything to do with adding video: you can tell so much more about someone watching a few seconds of them moving and talking than you can staring at a stack of photographs. When I think about "why aren't profiles on these apps videos instead of photos", only having photos feels stupid in retrospect, but apparently other people disagree.
https://www.theverge.com/2017/5/17/15561800/dating-apps-vide...
"The Internet is Moving to Video, but Dating Apps Choose to Arrive Fashionably Late" "Everyone wants to be Snapchat, except your dating service"
> “I’ll admit it: video is scary,” says Behzad Behrouzi, who oversees product operations at Lively, a video-based dating app. “You’re showing off so much more of yourself than if you just posted a selfie. You’re showing your flaws, your personality, the real you — and that can be terrifying.”
> Behrouzi calls video dating largely uncharted territory, but points to Snapchat’s success as an admirable model. “You’re sending videos to friends,” he says. “With Lively, you’re posting/sending videos to people you don’t know, which can be intimidating.”