I feel like the data they're using to project their number is an incomplete set. It seems like they said here are the number of students and number of jobs over the last 2 year...BAM projection! Yet I feel like a more complete set over the past 10 years would show that the rate of students pursuing CS as well as the job inscrease rate are scaling at an increasing rate each year, not just a steady incline.
Aside from my issues with the data, it is a thought that does exist and is of a moderate concern. With so many people out of work and so many technology jobs open in the market, it's a wonder that more people don't recognize the gap.