Threads testing federation via ActivityPub

I just saw this post on Threads:

https://www.threads.net/@zuck/post/C0zXcQmxO77

"Starting a test where posts from Threads accounts will be available on 
Mastodon and other services that use the ActivityPub protocol. Making 
Threads interoperable will give people more choice over how they 
interact and it will help content reach more people. I'm pretty 
optimistic about this."

I haven't been able to probe WebFinger for threads.net accounts, nor do 
Threads URLs reply with Activity Streams 2.0 content.

```
curl -H "Accept: application/activity+json" https://www.threads.net/@zuck
curl -H "Accept: application/activity+json" 
https://www.threads.net/@zuck/post/C0zXcQmxO77
curl -v 
"https://www.threads.net/.well-known/webfinger?resource=acct:zuck@threads.net"

```

Has anyone else been able to find signs of this "test" going on?

Evan