Nope. The new copper lines aren't made any thinker then the copper lines of 20 years ago.
And the copper tubing in the coils is made thinner then it was 20 years ago.
One thing that has changed about copper lines is that they are now mixed with some alloys that make them a little less flexible and more prone to kink. I have noticed that they also take more heat to solder together and that they wont take a lot of vibration to make stress fractures. One plus side is that they can rub against something longer because of what they are made out of!