Unlikely. Those Seinfeld ads didn't actually try to sell anything. A bit of overpriced, mild brand reinforcement most likely would not have affected the company's short-term prospects.

By the way, what M$ is doing here is very screwed up. They're laying off the first batch (1400) immediately, but using the remaining 3600 as a threat to make competition cutthroat. I might just quit if I worked there.