Not sure exactly what you’re asking, but it’s opt in.
So since I opted in, my mastodon account is shown as a bluesky account on bluesky.
But I can only follow bluesky accounts from mastodon if they’ve opted into the bridge, which seems to be a decent number, but still a small proportion. And the replies to my posts that are on bluesky, will only be visible to me from mastodon if the people replying have opted into the bridge.
Not sure exactly what you’re asking, but it’s opt in.
So since I opted in, my mastodon account is shown as a bluesky account on bluesky.
But I can only follow bluesky accounts from mastodon if they’ve opted into the bridge, which seems to be a decent number, but still a small proportion. And the replies to my posts that are on bluesky, will only be visible to me from mastodon if the people replying have opted into the bridge.