@kim It was done for a specific reason: floss.social/@rdnielsen/112367…
The test was not whether the Mastodon server with the post would handle it, it was about the link in the post.
When the other servers received the post, they would all go to the linked site and fetch the thumbnail for the article.
At the time, this other site that had recently started posting on Fediverse had complained that this fetching was causing too much load on their site. Many people were questioning whether that would really be an issue on a decent setup, so @gamingonlinux ran this thread as a test.