In Canada, a pension plan must be run by an independent fiduciary, not the company. Usually contracted to some financial institution. The fund must be diversified and the company cannot dictate the investment strategy. Every 5 years, the fund managers must do an assessment (“if we closed the doors tomorrow, everyone laid off, is there enough to meet all future obligations?”). If the fund is undefunded, then they must have a plan to get caught up in the next 5 years.
The same applied to retiree benefits. They must be fully funded, not paid out of operating.
As a result, there’s a lot less of the “double-whammy” - fund full of company stock, meaning during a downturn the stock is worth less, and that is the time the company has to pony up a lot more. Very few funds go broke and fail to meet obligations. (Unllike say, the US airlines habitually did)
Also, out of concern for worker mobility, all pensions must vest within 2 years - and a departing worker can opt to get a withdrawl into a locked-in savings plant or wait until they become eligible to collect.
But… in a downturn like 2000, where the market and interest rates both sucked, this was a double whammy for firms. It’s one reason why companies abandoned defined benefit plans. But then, American companies found this out too.