I received the "You are in" email, the link directs me only to Discord, am I missing something is it not a standalone software that I can download?
It is confusing for anyone who has not heard of Discord. I downloaded the app until I realized it was not necessary, then deleted it.
Discord is another channel for users to share feedback on Firefly. Like you said, it isn't necessary - you can use this community or Discord based on your preference.