<blockquote class="reddit-card" data-card-created="1588774544"><a href="https://www.reddit.com/r/VALORANT/comments/gdyrsg/i_also_decided_to_edit_at_2am/">I also decided to edit at 2AM</a> from <a href="http://www.reddit.com/r/VALORANT">r/VALORANT</a></blockquote>
<script async src="//embed.redditmedia.com/widgets/platform.js" charset="UTF-8"></script>
Haha you two want that, but have you considered what Reddit wants?
Since they changed their whole philosophy and started the v.redd.it thing it is not the same anymore.
All OpenGraph and Twitter Card tags give us a static image. Reddit is pretty clear on only allowing a static image to be embedded.
If you did further, you find that the video is in a DASH container, so audio and video are separate files. Getting that to play on Discourse means, at least, using a custom JS video player.
But the video then disappears when the post is submitted.
Adding allow="autoplay 'none'" on the end of the iframe element does then made the video appear, and it then plays fine with all the embed controls working (pause, play, etc):