No, it’s got an active community and fresh developments, so it’s definitely not dead. The concurrency story is/was poor, so some people left Ruby but many remain and many still join.
I would love to read or watch any content you have created about this project. It’s literally a goal of mine, to build something similar. I love helicopters and live under a flight path that’s used for by the rescue choppers, and I run outside to watch them every time. I’m going to start collecting ADS-B data also; I can imagine that’s complimentary to your efforts.