This would be helpful for web-platform-dx/web-features#84, to be able to create a spec URL validator that checks if a URL like https://w3c.github.io/webrtc-pc/#dom-datachannel-binarytype is a good spec URL.

A similar problem is solved in Bikeshed by downloading the data directly from GitHub:
https://github.com/speced/bikeshed/blob/584813e6380533a19c6656594c810bf974854e68/bikeshed/update/updateCrossRefs.py#L236

For something that should go into a CI check, that's not good though, since the build could break at any time.