That's not how I read it, but I'm not going to claim to be a fediverse expert. That post specifically says:

Provided that a Third Party User is followed by or following a Threads account, Meta will ingest these pieces of data specifically:

To me, this reads as, even if a Threads user follows you, your info gets chewed up by Meta.

In other words, if you post somewhere on the Fediverse, and some Threads user bumps into it, they can follow you, and that will send all that data to Meta. And it looks to include data well beyond the post the Threads user saw.

To me, this is a "sound the alarm" moment. If you came here to avoid Meta's data harvesting, this sounds like you at least need to be on an instance defederated from threads, but I'm not sure even that's enough.