We've changed the link from https://youtu.be/nRtp9NgtXiA. Please submit the full URL, since HN kills links from shorteners as they break the referential integrity of the post.
On a mobile device using a native app, it is quite hard/impossible to get a different url. Could you whitelist the youtu.be url ? because I'm guessing this will start to happen more frequently.
Mobile versions have the 'm.' subdomain, and provide a less optimized experience for desktop.
I would also argue that the youtu.be link is a canonical form, since the identifiers are identical to the source. It is just an optimized canonical proxy.