Switching pitching arms

I understand from the recent “Venditte” rule change that the minor league rules are that the switch pitcher declares his choice of arm to pitch with before the batter declares, and each can switch just once during a single AB unless a pinch hitter is used mid AB then one more switch is allowed.

I also understand that IBAF rules do not allow switching of arms within the same AB.

but the copy of the MLB rule book that i have says nothing relating to this situation. Does that mean i could conceivably switch pitch to pitch?