Yeah, right. Ever heard of PS2 (March)?
That launch was soooo horrible. It would have sold so much better in December...
And really, I'll say it again: I doubt that it matters much when the console launches, when we are talking about the first few days. Do you think a person that wants a next-gen console day one is like "oh, PS4 doesn't launch during the holidays, so I'm not gonna buy it. Too bad". Aren't the people who buy consoles at launch pretty much hardcore gamers?
The sales will go down considerably immediately after the launch, because it's February, that's for sure, but the negative effect is probably pretty negligible during the first 2 days.