A new Anniversary Update Cumulative Build has been sighted on Build Feed with version 14393.442 as being tested internally by Microsoft for Redstone 1 for Windows 10 and Windows 10 Mobile.
The new build has been compiled on 21st October. This would be another new Cumulative Update to be released by the company for Release Preview Ring Insiders. Currently we are not sure as to what fixes the new CU will be bringing for Redstone 1 Insiders.
— BuildFeed (@buildfeed) October 25, 2016
If the company does not find any new bugs or issues during internal testing then we could see this new Cumulative Update getting released to Redstone 1 Insiders in RP Ring by end of this week or early next week.