If you block the ORPort, won't the reachability check fail?
Fine question. At least this has been the case in the past, though I know there was discussion and maybe development to overcome this weakness. But even if it's not possible yet, having bridge contact information would allow us in the _future_ to reach out to bridge operators to inform them that they don't have to keep their OR port open anymore, and maybe even shouldn't.
https://trac.torproject.org/projects/tor/ticket/7349 https://trac.torproject.org/projects/tor/ticket/17159