The dates are indeed the same.
The 15.7 dates, when published, were put much further out than is typical for a release to help calm concerns as SAP was absorbing Sybase.
I don't think there are any plans to push the 16.0 date further out.
I expect the next major version will be released before 2020 and that it will have an EOL date that is further out (but don't have any solid knowledge, this is just extrapolating from what we have done in the past).
-bret