Arbitrarily blocking an actor at the protocol level is directly contrary to the entire point of decentralized protocols in the first place.
I know, Meta bad, but the fact of the matter is that they probably won't be defederated by everyone, actually, because the idea of being able interact with your real friends and family and other people you know is going to be enticing.
Edit: I just woke up when I wrote the original comment and I can see that it's not the clearest piece of text I've ever produced. What I meant is that I fully agree with defederating (and I'll do it on my instance), but I don't think censoring Meta in the core technology (ActivityPub) is the way to go.
It literally is, do you not see the power dynamics here? If the fediverse is to defend itself it must at all cost not federate with Meta or we will end up like XMPP.
Changeable definitely, would have to think about whether default block is the smart thing to do. It's hard, I really dislike Meta, but on the other hand if you go censoring instances by default, where does it stop?
IMO this should be the job of articles that tell you how to setup Lemmy, mentioning something like "Note that by default you also allow Meta the access to your instance which might mean privacy breach, here's how you disable it."
Many admins are lazy, and they expect their software to run well on sensible defaults, most won't care and just go with whatever the devs consider to be fine.
By choosing wether Meta is blocked or not by default the fediverse will have to take a stance.
Do we allow extremely powerful corporations that want to monopolize their influence but we get a user surge in the short term.
Or do we block them by default and anyone making an instance should make the concious choice to join the corpo-verse themselves so we can continue to foster a healthier alternative to whatever they are cooking.
Meta doesn't need Lemmy/Kbin/Mastodon. They are competing with Twitter. Threads will probably have more users than the whole fediverse combined within the first few days.
That's known, but it's foolish to think that for example Mastodon isn't seen as a Twitter alternative. Meta knows that and I think they want to not just be a corporate alternative to twitter, they want to make sure they are the alternative to twitter. The Fediverse has to take measures defending itself or Threads will overtake and stomp over everything, even if the sudden user surge might be appealing to some.