Microsoft might be getting ready to release a new build to the Stable branch. The build with version 10586.494 might be the new build that will be getting released to the Insiders on Release Preview and also to Non Insiders today.
The above build would be another cumulative update which the company might be rolling out to the stable branch . The build does not seems to add any new features but will be rolled out to fix bugs and improve the overall performance of the OS.
The news is not yet confirmed by the company so take this news as a pinch of salt and hope that the company releases the new build today to insiders on Release, Production and also to Non Insiders.