Is OAuth2 supported with Google Gadgets on Google Sites?

My various Google gadgets built into Google Sites broke yesterday with Google's legacy OAuth1. I cannot find a working example of the oauth2 gadget that works on google sites.

Can someone kindly confirm that this should actually work and do you have an example? :)

I'm afraid a note on this page: https://developers.google.com/gadgets/docs/basic

Note. Writing OAuth gadgets is no longer supported.

spells bad news for me!