For anyone coming back to this page in the future. Here is a
mildly pretentious Porsche video on the topic that sums up brake squeal with high performance brake rotors and pads.
moral of the story, brake pads vibrate at low speeds and the rotors act like a speaker.
Different rotors will have different common frequencies that produce a squeal. The brake lube put on the back of pads works because it dampens those vibrations thus helping to minimize or eliminate the squeal. Different pad material may vibrate less which is why some people see a reduction in squeal when they change to a new pad.
This is all completely normal and will just come down to whether you can stand the squeal or want to "fix" it.
Side note, when I bought my 350, I told them about the brake squeal and asked them to put some brake lube on the back...the guy just mumbles under his breath something to the affect of "that won't do anything" and proceeded to shave the rotors instead, which helped for a bit, but was not a more permanent solution.