There was a model from the shipyard that showed an aircraft carrier in a construction dock... circa 2014. That was actually the first indication of the layout of 003. In other words: the construction plans for the aircraft carrier must be very old.
Because aircraft carrier 003 has the same propulsion engine arrangement as aircraft carriers 001 & 002, but a new division of the watertight compartments in the hull (especially the side protection, we were able to clearly observe the differences between 002 and 003 during the construction phases), I assume 003 was planned from the day access to the Varyag was gained.