Part of a major pension is discretionary investing—let the experts make the decision. When you say “choice”, the person looking after the fund determines where the money should be and how they should be investing it, so the choice is really left to them to make sure that there is....
People coming in may be in different pools inside that plan. They can set that up, but as long as the person running the plan is the one making those decisions.... You shouldn't ask an individual if they want to be in foreign bonds or foreign this or that or something else. It should be left to the experts to determine: because of their age, experience, and savings, this is where their money should be. It's not the choice within the plan; it's the choice of the individual.