It would be nice if either this article or its linked one had some hard numbers. For example, how much would it cost a $100k employee with 25 years of service and 50 years old buy up 30 years and how much more per year would he get as retirement payments?
Well, if it’s sane, then the amount he’d have to buy would give years of contributions (which would still need adjustment for npv). Pensions are typically based on a 6% rate of return or so, so it’s probably a net gain to the state is they do this.