No, not necessarily. It depends how you structure the policy, most insurance contracts give you the ability to nominate beneficiaries for proceeds, which is a critical estate planning tool.
There are however many potential pitfalls to take into consideration, amongst others probate (the application to wind up an estate in many international jurisdictions) and where to pay the proceeds overseas in the case of minor beneficiaries. The use of a foreign trust could be a handy tool to ensure an optimised solution.
Special acre must be taken around all the provisions of the Estate Duty Act 45 of 1955.