I can't seem to lay hands on the story, but I recall seeing something from Paul Thurrott or Mary Jo Foley in the last week that indeed MS is planning two big releases for 2017, both around Redstone 2 (the upcoming Insider Build series code name). This actually sounds like a pretty well-founded rumor.
That said, your own source ultimately tracks back to a Microsoft Windows for IT Pros blog post that includes the following language, though:
"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."
If you ask me, that official statement more or less confirms it as a plan rather than a rumor. But of course, plans are always subject to change...