PeerTube Is Not Preseeded As A Trusted Site

YouTube is able to autoplay in browsers with the same media engagement score chrome://media-engagement as PeerTube because YouTube has been hard-coded as trusted into browsers based on a dynamically generated list using a variety of trust signals that marks YouTube as a trusted media site Chromium Preseeding

Therefore the only way to resolve the discrepancy is to add PeerTube to the preseeding which can only be done by increasing the global traffic and trust signals that PeerTube has. To confirm this I ran a test with both YouTube and PeerTube having the same Media Engagement score and YouTube is able to play but PeerTube is not because YouTube has a hard-coded trust signal built into the source code.