According to MSPU, the Windows 10 Creators Update will be coming in April 2017. MSPU apparently found a reference to 1704 and believes that we will see the Windows 10 Creators Update in April.
"Per my [MSPU] sources, Microsoft will be releasing the Windows 10 Creators Update this April. While the update initially had a version number of 1703 in Insider Builds leading to speculation that it would be released in March 2017, we can reveal that the final version number will actually be 1704 for an April release. This is not the first time that Microsoft has changed version numbers in Insider Preview releases, the firm previously changed the Xbox’s Anniversary Update release number from 1607 to 1608 last year."
MSPU believes that Microsoft will finalize all of the features that will be in the Creators Update by the end of January 2017. Once the Creators Update features are finalized, Microsoft will likely begin working on Redstone 3, the next big and untitled Windows 10 update. Microsoft has stated that 2017 will bring us two Windows 10 Redstone releases, according to Microsoft's Nathan Mercer:
Windows 10, version 1607 is our third Windows 10 feature update released. Based on feedback from organizations moving to Windows 10, this will be our last feature update for 2016, with two additional feature updates expected in 2017.
For now the April 2017 release of Windows 10 Creators Update is just a rumor. Whether Microsoft decides to release Windows 10 Creators Update sooner or later, we will just have to wait and see.