Is there any reason to suspect it's something besides the person behind the content requested their domain be excluded? Or IA behaving as they legally should and always have?
Are the content owners complaining about a desire to be archived but IA is blocking them? As if not, I don't see the issue.
I'm sure there's some guideline somewhere giving themselves blanket excuse to do anything they want, then hide behind secrecy and hope people will assume the best. What I'm not sure is why such duplicity being "standard" makes it any better.
Yes, they are legally required to listen to the copyright owner's request. In your linked example, that was the church of scientology. In your earlier post, that would be whoever was writing the tweets. Twitter could also choose to block their requests as the wayback machine would also grab their copyrighted code, but choose not to.
You're making a documented legal requirement sound like a shady partisanship. Unless there are examples of these people wanting their content archived and the IA refusing, I don't see your point. Anybody is free to tell the IA not to archive their copyright material.
Unless keeping the cause of removal secret is also a legal requirement, then this is by definition shady. And you assume that because some removals are results of legal complaints, then all are. It is Archive's choice to keep us in the dark regarding removals, and it is our choice not to trust them for it.
We aren't being kept in the dark, we know the reason some content is unarchived and they say which content is unarchived.
Your complaint is like going to a store with posted hours after closing and demanding an explanation for why they aren't letting you in. It's possible there's some vast conspiracy to block you from shopping, bit it's more likely they're following the posted rules.
Because of their deliberate policy of secrecy that forces you to assume, instead of know. As this is the 3rd time I repeat this same point, it will also be the last.