This is a pattern that I have seen quite regularly in recent times, mostly via Next.js, I think:

  <link rel=preload href=FOO.js as=script>
  <script async src=FOO.js></script>

That is, a preload, followed immediately by using it (rather than using it much later in the document, as was the original intent of preload links).

(On this submission, servers.json receives this treatment. While talking of servers.json, two things are odd about it: although served as JSON, it’s actually JavaScript, and a random cache busting parameter is added to its query string, rather than the server just instructing the client not to cache it.)

I cannot imagine any way in which this makes sense: the preload line should be 100% superfluous (and thus mildly counterproductive). Is there some utterly bizarre reason why this does actually help things, or is it just simple cargo culting of a corrupted idea as I presume?