The Amp javascript can be self-hosted [1] away from Amp's servers, there's even a framework demonstrating how to do it [2].
The only difference is that it doesn't pass Amp validator, which is necessary for the Bing search result icon. Developers have requested the feature for the Amp validator to include self hosting but it hasn't been added yet (or have any plans to AFAIK).
[1] https://gist.github.com/mdmower/b56e94f0dc36beafb825b0c5e31f...