Theme developers can finally rejoice. For the first time, it is now possible to pass data to templates via the various core template-loading functions. Enrico Sorcinelli announced the change on the Make Core blog this past Friday.
The feature was originally proposed by Scott Kingsley Clark in 2012. Over the years, the ticket has received a dozen patches. It has survived a closure and arguments over why the feature should not go into core. Sorcinelli was a primary driver that kept the ticket alive for the last few years.
WordPress developers have been cleaning up some old-but-useful feature requests for