I believe Sony was always pretty proactive about being in stock, even with several positions in the top 10 for best selling systems in November/December of any year since 1995. and having several months after launch in both America and Japan of batshit crazy monthly sales. The only time I remember massive shortages after the launch window was when they introduced and subsequently screwed themselves over of several hundred thousand sales with the PSTwo.
Sony would've opened up a plan...oh yes, they surely would've
So would I, of course. A bird in the hand is worth two in the bush. The more money they make right now is better than playing it cautious and underproducing, opening the door for MS or Sony to develop their own groundbreaking, earthshattering, dick-hardening motion control or something else entirely, along with their own 'Wii Sports' It could very well happen and then Nintendo will wish they had produced more of their highly profitable Wii console in the time that they had in the spotlight.
All of this is highly speculative and unfounded, of course, but I am just calling it as I see it.