ugh... I'd noticed the change in behavior for following links to posts and profiles *within* the web app on #Mastdodon 4, but I hadn't looked to see that the *actual* post and profile web pages do not actually contain the post or profile content, just JavaScript and the metadata to load it.
https://snarfed.org/2022-12-03_48181
In essense, Mastodon profiles and posts are no longer actually interoperable parts of the web. Or as #indieweb puts it: #jsdr