No, it does not mean that the gamepad was the first priority. All it means is that mouse and keyboard input require more development. Reading anything more in and then claiming what you read in is evidence of dishonesty is no way to make an argument.
Given the circumstances and a small dose of speculation, I think it's fairly safe to make that assumption. We've already passed 2 release dates, and what we can now see is that gamepad input is ready, while M+K is not. And this shouldn't really come as a surprise, as it is understandable from a business POV - the console market is much bigger. Development priorities are dictated by where the money's at, after all.
I'm not sure it's wise to take what the devs say at face value all the time. Look at how PR talk a la "genre-defining, truly next-gen audio-visual fidelity" turned out so far.