Threads’ fediverse beta opens to share your posts on Mastodon, too

Threads is rolling out fediverse sharing in the US, Canada, and Japan. The feature is still in beta, and you’ll need a public profile to toggle it on.

The Verge
HOWEVER---- it's a one-way integration. Your Threads content goes out, but you can't see replies, follows or for that matter, follow or see other posts in the fediverse.
On the fediverse side, you'll have the chance to directly follow those accounts on Threads and get the content first hand (instead of thru a bot), but you won't be able to interact with them.