Question: Why are some instances defederating instances which don't sign the fedipact?

Something I don't understand currently about the whole Meta/Threads debacle is why I'm seeing talk about instances which choose to federate with Threads themselves being defederated. I have an account on `mastodon.social`, one of the instances which has not signed the fedipact, and I've had people from other instances warn me... #fediverse

https://kbin.social/m/fediverse/t/145147

Question: Why are some instances defederating instances which don't sign the fedipact? - Fediverse - kbin.social

Something I don't understand currently about the whole Meta/Threads debacle is why I'm seeing talk about instances which choose to federate with Threads themselves being defederated. I have an account on `mastodon.social`, one of the instances which has not signed the fedipact, and I've had people from other instances warn me...

People threatening to defederate from mastodon.social is a core part of the mastodon experience. Nothing new, and happens around pretty much every drama.
But in this particular case, it’s how the fediverse kills itself. By demanding a monolithic approach, ironically.
If you think that 16 million users day 1 is business as usual then you are naive.
Where are people getting these numbers from? I've seen three people so far each give a different number for day 1 signups (probably bc today is the first day), but I'd like to know the source, please.

30mil users already, as per Zuck himself on Threads.

https://www.threads.net/t/CuXCjGVrd6R/?igshid=NTc4MTIwNjQ2YQ==

Mark Zuckerberg (@zuck) on Threads

144K likes, 24K replies. Wow, 30 million sign ups as of this morning. Feels like the beginning of something special, but we've got a lot of work ahead to build out the app.

Threads
Sry, can't open the link since I'm in Europe, but I guess the source is just Daddy Zuck then. Thanks!