But it doesn't end there... they block the CDN that implements this feature, and then the CDN's customers--who probably didn't care much about the benefits this gives to some of their users but are now losing access to some large customer base--start complaining and migrating off the CDN, which results in the CDN pulling back on the feature.

And we know this is what will happen as this is effectively what happened with domain fronting--where you simply use the wrong SNI instead of hiding it entirely--with all the large CDNs actively "fixing" this feature to prevent their customer's websites from being blocked by firewalls because of users who were using this to get around hostname restrictions.