The metapackage emacs (47.0~exp1) resolves this issue and it is in experimental since the last december. It is just a metapackage which depends on emacs25 instead of emacs24 and nothing else.
Please, bring it to Stretch before its release, this package doesn't introduce issues nor new software and it allows us to jest get rid of emacs24. Right now additional packages in Stretch for Emacs, such as elpa packages, work with both emacs24 and emacs25 but they strictly depend on the emacs (46.1) metapackage which depends on emacs24 only. So we have to install both version of emacs!
