That is true if the aircraft is instantaneously rotated around an axis perfectly aligned with the airflow.
But it's not real life. In real life, even at maximum roll rate it takes time to go from 0 to 45 degrees. It also depends on the skill of the pilot, but lets assume the pilot can fly the roll perfectly.
As the pilot begins the roll the lift vector is pointed to the side, which would begin to turn the aircraft. To prevent the turn, opposite rudder is required and the aircraft is in uncoordinated flight. At 45 degrees, the wing provides half the lift, and the side force on the fuselage due to uncoordinated flight provides the other half. The wing and fuselage produce equal and opposite sideways forces which means the aircraft does not turn.
The wing is providing half the vertical lift at a 45 degree angle. That requires less total lift than supporting the whole aircraft at zero degrees bank.
To fly it perfectly, the rudder needs to be increased and AOA of the wing decreased as the aircraft rolls from 0 to 45 degrees.
That is for a 45 degree coordinated turn, not a roll. A turn is totally different to a roll. In a turn, lift required increases as bank angle increases. In a roll, lift from the wing decreases as bank angle increases.
At 90 degrees angle of bank in a roll (knife edge flight) the lift required from the wing is zero. At 90 degrees angle of bank in a turn the lift required from the wing is infinite i.e. a coordinated 90 degree banked turn is impossible.