(a) An incapacitated person for whom a guardian has been appointed retains all powers and rights except those powers and rights which the guardian is granted.

(b) Subject to subdivision (a) of this section, the appointment of a guardian shall not be conclusive evidence that the person lacks capacity for any other purpose, including the capacity to dispose of property by will.

(c) The title to all property of the incapacitated person shall be in such person and not in the guardian. The property shall be subject to the possession of the guardian and to the control of the court for the purposes of administration, sale or other disposition only to the extent directed by the court order appointing the guardian.

(d) If the court determines that the person is incapacitated and appoints a guardian, the court may modify, amend, or revoke any previously executed appointment, power, or delegation under section 5-1501, 5-1505, or 5-1506 of the general obligations law or section two thousand nine hundred sixty-five of the public health law, or section two thousand nine hundred eighty-one of the public health law notwithstanding section two thousand nine hundred ninety-two of the public health law, or any contract, conveyance, or disposition during lifetime or to take effect upon death, made by the incapacitated person prior to the appointment of the guardian if the court finds that the previously executed appointment, power, delegation, contract, conveyance, or disposition during lifetime or to take effect upon death, was made while the person was incapacitated or if the court determines that there has been a breach of fiduciary duty by the previously appointed agent. In such event, the court shall require that the agent account to the guardian. The court shall not, however, invalidate or revoke a will or a codicil of an incapacitated person during the lifetime of such person.