Maybe a different perspective, focus on the communal, is more preferred?
The discussion on what is, or even the use of, 'authentic' and 'local' is interesting. I find it's use in travel writing often annoying and even obnoxius, yet when traveling or living abroad as an expat, you often find yourself thinking along the same terms.
random:
- For me a 'meaningful interaction' would be; you connect with people over a certain topic (or multiple) in a non-travel / tourism related setting. Any guide activities or suggestions are an extra.
-is it a 1 on 1, 1 on group, etc?
- A local person does not tour the city (by themselves) per se, they just live their life.
- Being with a local for a while can be very insightful, yet it does not mean they can tell you much about x of their country / culture / city (and vice versa).
- you probably dont want it to turn into an index of 'the 12 unknown highlights you need to see' articles.
-look at it from the other perspective; the local. What would they like? OR in other words, how do you want to interact with strangers coming to your town?
How will you avoid it being taken over by men looking for sex? This was a serious problem with Couchsurfing.
What will it offer over existing communities like local subreddits, Couchsurfing Hangouts, Bumble BFF and others?
Those who aren't interested won't sign up, and it might not work out... but I certainly wouldn't dismiss the idea outright. OP may as well give it a try and see where it goes.
These are just the questions that I believe OP should ask before breaking ground on that project.
Make light use of software at first. Use existing tools to build a process before attempting to build an application.
Start with friends and family and their friends. Define the real problems that people have with current resources. What provides the most value to those who use your approach?
I have thought about this concept myself. There are usually very fun and interesting things to do and see in a travel destination that are not necessarily the primary, dry tourist attractions.
Travel memories are built around social engagements-talking, sharing, learning, experiencing. I think a solution that emphasizes these things would be beneficial and well received. But again, this will take some effort to sort out.
Good luck.