Matrix is right there. I recommend the matrix-setup-ansible repo. If full-fledge matrix is too much, you can use revolt which runs on the same protocol but has a much simpler mode of operation.

Matrix enables you to manage permissions like on discord, so you can even have a channel for announcements and a chat room where your users can interact with you.

If you want service interaction, matrix has many wrappers in many languages enabling you to make bots as you wish, and I'm sure the things you need already exist and are already made, so you would just need to instantiate the bot too.

The only real risk is if your users try to join big rooms federated from matrix.org. your server will start syncing a huge user list and their profile picture and it's basically toast.