Since the memo is a work product of the Legislative Branch, not the Executive Branch, the decision to release it to the public should rest entirely with the Legislative Branch not the Executive Branch. My 2 cents worth.
The decision still rests entirely with the Legislative Branch. It is the Legislative Branch that came up with the rules that allows the Executive Branch to review the documents prior to the Legislative Branch releasing the documents. If the Executive Branch objects, the Legislative Branch can overrule the objection thru a full vote of the House.