Windows 10 Mobile Build 14393.573 will be the next cumulative update for non-Insiders. Windows 10 Mobile Build 14393.479 is currently available in release preview ring. Build 14393.573 is still under testing and it will be released only if it passes the release criteria.
Microsoft has compiled Mobile Build 14393.573 on 30th November and it could be the next cumulative update for Windows 10 Mobile.
Windows 10 Mobile Build 14393.573 will include bug fixes and performance improvements. One should not expect any major changes from the upcoming cumulative update.