Most mechanics I know of here, put new rotors out of the box on a lathe to keep the returns to a minimum.
Driver habits can play a big part in perceived rotor warpage. Sometimes it is actually warped, sometimes they pulsing pedal is caused by brake pad deposits.
The deposits can happen if one brakes hard and then holds the brakes firmly while waiting at a traffic light. the brake pad will transfer an imprint of brake pad material on the rotor which remains grabbier and gives the pedal that pulsed feeling.
If I have to brake hard and wait at a traffic light, I take it out of gear and use my parking brake. Whenever I know my pads and rotors are very hot, I try not to keep the brakes firmly clamped on the rotors.
Some drivers keep so much pressure on the brakes when stopped that they will often cause the pad deposits and the pulsing. Many vehicles with reported rotor issues simply have higher idle speeds which require more pressure on the brake pedal to keep vehicle from rolling forward. Combine this with hard braking at the last second and the inevitable result is s pulsing pedal.
So not every pulsing pedal is caused by a warped rotor, it can be caused by uneven brake pad deposits, and these uneven pad deposits do not necessarily require a brake lathe or new rotors.
Properly bedding the new brake pads into new or old rotors is also a consideration. One wants a nice even transfer of brake pad material to rotor, and this means the initial drive it is extra important to not get the brakes super hot and then keep them clamped in one place.
The proper section of road to bed in new brake pads needs to be considered.
Not all brake pads say they need bedding in. The above pic is from my Hawk HPS brake pads which are not cheap, but have incredible stopping power, and very little dust.