@Satsuma I think some of them do use Article, but Mastodon translates it to look like a note with a link because it doesn’t have a native representation of Article. I half remember some discussion in the early days of Pterotype (an activity pub plugin for WordPress) over how to represent a post, but I can’t remember for sure.
@Satsuma Could be. I found the Pterotype discussion. Essentially it was: should we switch to Article even though Mastodon doesn’t display it very nicely? (As of 6 months ago.) Apparently Plume uses Article as well.