The 22nd of January, I received an email with the subject \'Important: Steps to migrate from discontinued Documents List API\' from Google Apps .
Imp
Short answer is no.
The Docslist API is being discontinued because it has been replaced by the Drive API. In the case of the Spreadsheet API, there is no replacement API (yet - maybe one day), so it remains supported.
The only gotcha is that at some point, only OAuth 2 will be supported for authentication/authorisation so if you're using OAuth 1 or u/p, you have some work to do.
The official Google response is that the Spreadsheets API will continue to function after the 20 April shutdown:
"Apologies for the confusing email. The sheets API is not yet deprecated and will continue to operate beyond the April shutdowns."
https://code.google.com/a/google.com/p/apps-api-issues/issues/detail?id=3709