@Victor Monsalve The updates to Microsoft translator are documented in the blog posts from the team here. With respect to the response from the API v3.0 the alternatives are still part of the response but I think that is only returned if the score is not absolute i.e <1.0 when the model detects that it could be a different language other than the one identified as most probable because alternatives is an array of all other languages with lower scores if the model detects them. The current API reference page still mentions alternatives as the possible value in responses.
I am also curious to check what is the sentence/text passed in the first scenario in the response from couple of months ago?