The Blower will not be federated with Threads. You won't see their posts, they won't see yours.
Why?
When we defederate (totally disconnect) from another instance, it's almost always for the same reason. A lack of trust. Every instance in this network has different rules, reasons, standards - and that's great. It lets people find a home and a community that suits them.
If an issue arises, we admins sometimes need to get in touch with our counterparts on the other side to resolve things. This could just be by forwarding reports of "hey this account is spamming people", or "this person is threatening that one".
In almost all cases, we trust that their actions will be compatible with the expectations of our local users. We start out treating instances as trusted. This is usually just fine.
Trust builds up over time, or goes down - but if negative interactions are bad or frequent enough, if it seems what they want and what we want are just totally different things, we cut them off.