Technically I think you are correct but I think the effect will be minimal.
For an example, I had been out of video gaming largely for almost a year and a half, then I heard the next nintendo console was launching so I got it, six months later I have purchased (including the Wii U of course) around $1000 worth of gaming related items (including a PS3 to catch up on the sony/3rd party stuff I missed as a Wii owner)
I could see the oposite happening, ie someone whose main gaming systems are usually sony and/or microsoft reignites their gaming passions with a new release and decides to pick up a Wii U as well (or a little later) to get the games they will miss, and the other example of people buying a Wii U because the PS4 and/or XBox are out of stock. But I think these will have a very small effect in the bigger picture.
Nintendo would be very smart however to use the time to launch a new advertising campaign and try to catch some of the buzz that will be going on at the time.








