This is a weak version of "uphold the social contract at all costs" mentality. Rather than uphold it because of the people that enacted the contract, we will uphold it because the people put in charge of upholding it want to stay in charge. Its a much more reasonable idea and if this is really the case then it's an unfortunate situation. That said I don't think its likely that the Swedish elderly are either contributing much to taxes or capable of revolting. The younger generations would actually react positively to it. For example I already have no trust that I will see a meaningful return on my social security "investment." I'd rather see it shut down than wait for the off chance that anything is left in 30 years.
I think democracies move too slowly to make changes like this, however. I don't think there is really any plan at all. I think that is ultimately the issue here. And unfortunately if the article is to be believed the "solution" of voting in what the article has called an extremist party may become reality. I think that's the real issue here. We can debate social contracts all we want but if an extremist party is voted in it shows that Sweden's plan was flawed from the outset.