It's getting the favicon, and while doing so gives information about the client in the user-agent and the IP-address.
How is this different from any other request to a website?
How is this different from any other request to a website?
It's not. Which is the point. The share menu is supposed to just pass a URL from Safari to another app. It's a glorified copy and paste, not a page load.
It's not. See the addendum to the blog post.
When you send a url through the share menu to a share extension that supports previews the share sheet needs to include: the title of page and a preview, and that's what's happening. Scraping the content from the currently open page would require the share sheet to be able to read state from the app triggering the send, or if the API allowed that app (safari in this case) to just include everything the app would need to do to a fresh request from an private context to give the best approximation of what the recipient would get, and so the "re-load of everything" would still be required.
Finally, even if the app did want to use the existing page state, people seem to like the open graph meta tags that provide summary text or images which may not have been loaded, so they'd have to be requested instead.
Says who?
It's used to show the icon and page title. That seems useful.
I think your expectations are unrealistic. If it's somehow extremely critical you don't actually make any requests to this URL then you're already playing with fire here, as it's not too hard to accidentally click the wrong mouse button or whatnot.
How so? Please explain how the iana.org icon in the blog post screenshot is useful.
Moreover, as the Addendum explains, that information is not even passed along to the other app when the URL is shared. It only appears in the share menu but ironically doesn't get shared.
How is that clear? I understand that someone inside Apple decided this was a good idea, perhaps for aesthetic reasons, but that's not the same as being clearly useful to people.
It seems to be yet another example of Apple bringing iOS UI to macOS.