The development of the next major Windows 10 update is proceeding smoothly and according to Microsoft's roadmap, it should be finalized as soon as next month.
So the release of RTM is a matter of time, and a publication at mspoweruser shows that we are much closer than we are expecting. The publication states that build 17746 may be a RTM candidate, but there is no official confirmation.
But even if this information is not accurate, Microsoft will have to prepare to complete the development of Windows 10 Redstone 5. Recall that the company's strategy is to update Windows 10 with great updates twice a year. So if the development of Redstone 5 is completed in September, and its public launch in October, we are on schedule.
Although it is too early for her Microsoft to sign RTM (this will probably be the end of September), the company will have to freeze the addition of new features to deal with bug fixes and performance improvements in the upcoming operating system.
Windows 10 Redstone 5 could be released as a October 2018 Update following Microsoft's tradition of naming and the previous version of Windows 10 April 2018 Update. The April update was expected to be released as Spring Creators Update, but the company eventually decided to re-name it to fit better with its timeline.