I’m not sure where you are getting the idea that it is only the documentation of Scrivener 3 that needs doing, as we haven’t yet said anything officially about the release of 3.0 or its status other than that we are working on it.
Also, if you don’t think that Scrivener’s documentation takes a month or so to write or update, you clearly haven’t seen our manual! It’s 550 pages long! It’s not the sort of thing you can rewrite in a week.
There is certainly nothing cynical about our timing, and we are not artificially holding anything back. 3.0 was held back by the iOS version, because I had to work on that for several months. But also, software needs testing.