The stream of refugees coming into Europe could be the boost it needs.
In 2003, the average age in Europe was about 37 years. By 2050, some analysts predict it'll rise to 52 years. This puts a huge burden on a population. The ratio of workers to retired people may drop to 2 to 1. Each worker will not only have their own costs but 50% of the cost of a retired person. That's tough.
The refugees streaming into Europe are younger and more fertile than the Europeans. Given there are millions of them, they might even be able to significantly lower the average age and to raise (albeit slightly) the ratio of workers to retired people.
European nations might look back at this as a lucky break, however harsh it seems now.