Here's what I said in Social threat modeling and quote boosts on Mastodon about approaches like an option about whether or not a post can be quoted in
"These limitations could have potential downsides as well. If a politician or some other public figure says something racist or anti-LGBTQ, should they be able to prevent people from quoting it? Mastodon's content warning (CW) norms are often racialized, with people of color getting told they need to put CWs on their personal experiences to avoid making white people uncomfortable. I could certainly picture similar things happening with requiring consent to quote.. For that matter, unless there are limits on who can ask for consent to quote, it's possible that bombarding somebody with consent requests could become a harassment technique in its own right. To be clear, though, these aren't necessarily reasons not to do these things, just factors that need to be considered in any design.
Of course, if people can't use quote boosts to do this kind of quoting, they'll fall back on screenshot-and-link or (if they have access) a media quote. There's no obvious way to prevent these. Norms about consent to be quoted could be somewhat helpful even if attackers ignored them ... once again, though, there are potential downsides. Still, as Leigh Honeywell disucsses in Another Six Weeks: Muting vs. Blocking and the Wolf Whistles of the Internet, a lot of harassment is low-grade, opportunistic, and not terribly persistent. Screenshot-and-link is more effort than a quote boost, so even if it remains an option, reducing abuse possibilities for quote boosts has value."
And I discussed the differences between screenshot-and-link and Twitter's QTs at length in the appendix of Black Twitter, quoting, and white views of toxicity on Mastodon
In general it's complex because directing attention to a post without pinging the author is useful for calling out problematic posts but also a vector for abuse. Given quote tweets importance to Black digital practices, and the racialized history of quote boost discourse on Mastodon, this is why I keep emphasizing the importance of ensuring that Black perspectives are heard and listened to during the design process. Of course those aren't the only perspectives that matter but they're critical and likely to be overlooked!