Skew also means to deviate in a certain direction. It is a term used in statistics and distributional math. If you ask everyone in a class to pick a number from one to ten and the average comes out seven, you could say the numbers were skewed
to the high side since you would expect the average to be five or six. In this case, the argument is that the high costs of training and benefits (retirement is a benefit) would cause companies to stay with older, more experienced employees instead of skewing
to a younger workforce.
In the US, companies set money aside to be invested so that their employees will have retirement benefits when the time comes. If they don't, they could easily run out of money or go out of business leaving their employees with nothing. This setting aside of money is called "funding" the pension.