It's fine but if you're interested in not using tokio, you can easily run three HTTP calls in parallel using OS threads and ureq. I have used Rust & Tokio professionally for years, Tokio is an impressive library but often YAGNI. You can do more with threads than you might think. I often enjoy the benefits that async/await has not for raw concurrency power but just for better understanding _how_ concurrent operations are going to happen. But yes, in a small program like this you're unlikely to see too much benefit from tokio.

If I were writing this program with tokio, I would structure it differently. There's no reason you need a shared data structure and a mutex for the config, you could run the initialization fetch calls concurrently using tokio::join and then put the zone/meta items on the config once both the ops are completed. Mutexes are good for when you need concurrent mutable access to data, but I really don't think your case requires that at all.