I choose sdf because it has typically been neutral on those regards. Let users choose whether they want to block whole instances or not. Federation is literally the word that gives meaning to fediverse, I don’t agree with the arguments who want to make the fediverse an “alternative” internet isolated from the rest.
I'd rather not defederate. Why? Because the fediverse is open by default and so far we haven't really limit-tested that philosophy. In my opinion, it is better to push the envelope sooner rather than later, if only so that we can learn from the experience.
If it doesn't work out, then so be it. We have the tools to fight back against culture-death -- this will not be Eternal September 2.0
Erin Kissane has an excellent article on why Meta doesn't deserve the benefit of the doubt. Meta/Facebook has had power over social media before and displayed incredible disregard for human life, much less anything else related to healthy communities.
To treat Threads the same as a brand new instance and federate with it is a mistake.
I freely admit that I don't know that much about ActivityPub or SDF infrastructure, but the issue of server load bothers me. Threads is huge and has all of FB's CDN behind it. The SDF crew are great, but this strikes me as a potential DDoS-level threat. Someone who knows more than me, please put my mind at ease.
On the one hand, I do think there is a risk of Meta's influence becoming too pervasive over ActivityPub and ultimately kneecapping it. I think to presume this couldn't happen is naive. Further, Meta does have a history of trying to bring everything under its own umbrella, and if they see enough profit opportunity in trying to own the protocol then they will sink serious effort into doing so. They have done it with many other companies & ideas already.
On the other hand, preemptive blocking is not in the spirit of the fediverse, users should be able to make their own choice, and SDF is known for its general openness. "Why in this case and not others?" is a real question.
I personally don't think the influx of users/content & problems with "Eternal September" are too big a deal. True, I'm not a sysadmin or mod here. If those were real reasons to block the service then we should do it on logistical grounds without hesitation - there's no need for user input or discussion in that case.
I am probably going to personally block Threads for myself, but IMO I don't really think that defederating is the right way to go for this instance. I think it's nice to have a place where I can get everything so I get to choose what to see. I'm not sure about elsewhere, but I really want to be able to see whatever is out there. IMO it would be a much more radical statement if a majority of Fediverse users (as opposed to a majority of instances, which is only reflective of those users privileged enough to run an instance) blocked Threads from their feeds.
I would recommend defederation. Meta has a long history of malicious information manipulation and helping drive the rot of the www.
Beyond that, they boast a user count that is an order of magnitude greater than the entire fediverse. This sounds, like a recipe for mods burning out from trying to keep the firehose of bad actors under control. Not to mention the potential server impact of caching posts, images, etc.
Curious how EEE is supposed to work in this case. Threads federates and then what?
The worst case I can think of is culture clash between a ton of Threads users and the rest of the fediverse Eternal September style but any scenario in which the fediverse becomes popular at a large scale by any means is going to eventually lead to this.
Google Talk adopted XMPP, and was compatible with other servers running XMPP. Google's adoption led to many new people starting to use XMPP through their service, and people using XMPP on other servers could now talk to their friends on Google Talk.
XMPP then attempted to create new features that would be adopted by every XMPP server, except for Google Talk. This led to incompatibilities, where XMPP users wouldn't be able to talk to Google Talk users for days at a time. The large number of Google users meant that XMPP couldn't just ignore Google users, and would instead have to slow progress to remain compatible with Google servers.
Things were still working for the most part until Google decided to stop allowing communication with external servers altogether. The users of Google Talk just saw that a few of their friends were offline, and nothing else, and users of other XMPP servers saw that a very large chunk of their contacts were now unable to be communicated with unless they created a Google account and started using Google Talk, which many did. Those who didn't lost the ability to talk to everyone that they used to talk to on Google Talk servers. Many people ditched XMPP after this.
Then Google went on to create whatever new proprietary messengers with extra features they felt like, starting with Google Hangouts, which people then adopted quickly, due to already using Google services as a messaging platform.