@TeamYouTube my 9 minute cartoon has been public for nearly 12 hours now and it's still very low resolution (uploaded at 1080p). Throughout my 10 years on YouTube, my low color cartoons usually only take a few minutes to process.
The availability of HD may take a bit longer than other resolutions. We are working to improve this! If you prefer to wait for availability of HD, you can upload your video as unlisted and make it public once that resolution is available.