If the terms of an instrument creating a power of appointment do not prohibit the power holder from revoking or amending an exercise of the power, a power holder may revoke or amend the exercise of a power only if one of the following apply:
(1) The instrument creating the exercise of the power of appointment may be revoked or amended.
(2) The power holder reserves a power of revocation or amendment in the instrument exercising the power of appointment.