Original source: https://oembed.com/providers.json (2021-05-09)

• Kickstarter because its oembed provides less data than using opengrah values
• Reddit because its oembed provides less data than using opengraph values
• Spotify because its oembed provides less data than using opengraph values
• Twitter because we have a rich resolver already
• YouTube because we have a rich resolver already

And a few more that can be diffed between https://oembed.com/providers.json and our providers.json file