If you want gnome-schedule back, you'll need to find a developer who wants to maintain it. If that's you, you will need to file an Intent to Package bug. If it's not you, you could file a Request for Package bug. You could probably convert this bug to one of those bugs if you want.
For more information, see https://www.debian.org/doc/manuals/developers-reference/pkgs.html#reintroducing-pkgs Thanks, Jeremy Bicha
