Threads is using the protocol that the entire fediverse is using, called ActivityPub. The protocol allows for lemmy instances to communicate with each other and with other sites like kbin and mastodon. What lemmy.ml did is called defederation, so threads can't communicate with lemmy.ml. This is to prevent meta/Instagram/Facebook from killing ActivityPub in the same manner Microsoft, IBM, and Google has killed open source protocols in the past.
The most notable one imo is Google semi killing XMPP. They started Goolge Talk based on XMPP and after many people started relying on it, they replaced XMPP with their proprietary protocols.
Threads is using the protocol that the entire fediverse is using, called ActivityPub. The protocol allows for lemmy instances to communicate with each other and with other sites like kbin and mastodon. What lemmy.ml did is called defederation, so threads can't communicate with lemmy.ml. This is to prevent meta/Instagram/Facebook from killing ActivityPub in the same manner Microsoft, IBM, and Google has killed open source protocols in the past.
The most notable one imo is Google semi killing XMPP. They started Goolge Talk based on XMPP and after many people started relying on it, they replaced XMPP with their proprietary protocols.