Yes, with a subreddit folks will already be registered so there's no barrier to participation. On the other hand, because there's no barrier to participation then perhaps worse s/n ratio. But noise is better than silence.
So I saw the page and will probably sign up. However, there won't be a strong motivation for me to come participate unless there is a) A minimum threshold of folks who use it actively. or b) I keep seeing it in my feed. I visit HN and reddit every day and that is easier for me to participate in.
