Autoloads file no longer written when none need to be generated?

[Radon Rosborough]

As of commit 03d94198 [1], it appears [2] that the behavior of
autoload generation has been changed. Before this commit, if
`update-directory-autoloads' was called and no autoloads were declared
in any files in the directory, then an autoloads file with no
autoloads would still be written. After this commit, no autoloads file
is written at all. Was the change intentional? And will it be here to
stay?

Best,
Radon Rosborough

[1]: 
https://github.com/emacs-mirror/emacs/commit/03d941982fbdf96260fc47d1cafbdda78c1d128e
[2]: https://github.com/raxod502/straight.el/issues/104#issuecomment-317075966