If this "privacy setting" for #quoteposts is implemented with it enabled by default, the result will be disastrous. :reisensweat: Since there is no other way to enforce this setting other than #defederation, we are going to see Mastodon servers strong-arming those software developers who are "non-compliant" by threatening a #fediblock. :reisensweat: Developers of the -key and -oma families will suddenly have to scramble to make their implementation of #quotetweets compatible with Mastodon's "privacy-friendly" implementation. :satsuki_sadge: This way of "extending" the fediverse is not acceptable, and everyone who has opposed #Facebook joining the fediverse due to #EmbraceExtendExtinguish should also oppose this issue which just eventually leads to the same result.
Mastodon might introduce a "proprietary", home-brew "No quote-toots allowed" flag outside the ActivityPub standard that probably won't be documented anywhere. Just like their "sensitive image" flag, but even more critical.
And if that happens, all Fediverse projects that have a quote-post/quote-boost/quote-tweet/quote-toot/share feature will have to have that flag reverse-engineered from Mastodon's source code and implemented a functionality that greys out the corresponding button under "no quote-toot" posts. And all their instances will have to upgrade to a version that fully supports that flag before Mastodon rolls out that flag. Or else Mastodon will defederate all their instances for being non-compliant.
This will at least affect Friendica and everything that can be traced back to it, including Hubzilla and (streams), as well as Misskey and everything that can be traced back to it, including Firefish whose development is dead and dozens upon dozens of other Forkeys.
If this actually comes, and if it's enforced immediately after release with no grace period, Mastodon could just as well fully be defederated from the rest of the Fediverse due to being incompatible. It'd cause a rift between Mastodon and the non-Mastodon Fediverse anyway because the former would have a requirement for federation which the latter is incapable of fulfilling.
Well, cough the powers-that-be think handing out #BirdSite features like #QuoteTweets is much more important, even though they staunchly explained why those features should never and would never be on mastodon at the beginning of the #Twexodus. :P