No, joint-life annuities can be paid out to any beneficiary, if this is agreed when the annuity is bought.  If an individual dies under the age of 75 with either uncrystallised rights or unused funds remaining in a drawdown pension, a beneficiary's annuity bought with the funds is paid tax-free.
However, the above does not currently apply to scheme pensions. This means that the payment of a dependants’ pension paid from a defined benefit scheme will continue to be taxed at the dependant’s marginal rate, regardless of the age of the individual when they died.
HMRC Pensions Tax Manual PTM072200: Death benefits: types of pension: beneficiary's annuity HMRC Pensions Tax Manual PTM072110: Death benefits: types of pension: dependants' scheme pension: conditions