Hey, this is Ankit from Teams Calendar, Bangalore team, India. We own Teams Web/Desktop Calendar.
We are working on migration of exchange calendar APIs from EWS to REST protocol. We actually started this even before announcement of REST API deprecation and has rollout new APIs to Teams lower rings.
I saw message regarding deprecation of OAuth Sandbox website. We rely on it for integration and testing purpose. What's the alternative for it? It will very hard for is this is deprecating and there is no other alternative.
I know guidance is to move to Graph API but we are in middle of current REST migration and continuing on same.