Well fear not: Boomer private retirement accounts don't hold most of the stocks.
What's really going to be challenging for capitalists is losing the whole "It's good for your 401K!" justification when nobody actually owns enough stock to care. Only 45% of millennials have retirement accounts and only 33% of millennials have one they are actively contributing to[1]. The median balance also shows them getting a late start [2].
Defined benefit pensions for government employees are invested in the market too, and everyone is exposed to that risk by way of being subject to taxes.