It only makes sense. No employers would allow their employees to sign up to the contract, if this weren't included, because it excludes civil liability in relation to things that are not any doings by them. If the employers are not responsible for deciding where to administer the funds or where to invest them, they need to be exempted from any liability respecting those matters, because they would be lumped together in a lawsuit.
If, for instance, 10,000 employees wanted to sue the administrator of the fund, they would be part of that lawsuit, if they're not excluded. Why should they be part of a lawsuit in relation to decisions they had nothing to do with? They're just there as part and parcel to help facilitate the employee and the administrator of the fund.