Tesla windshields seem to be little different from other windshields. None of they are built with optical precision, but are two sheets of flat glass sandwiched with a thin plastic membrane between them (safety glass). They are flat float glass, sandwiched and then heat molded to the final curvature. Some people are more sensitive to others for imperfections.
If just a few new owners complain on the forum, this will make it seem like it is a common problem. Often it is just the nature of windshields, and if the distortion is right in front of you, that will make it stand out more.
While, nothing is perfect, it seems that if the distortion is obvious and significant, they will replace it. If it is "within standards" they will ask you to accept it.
Tesla has recently begun putting sandwiched glass in their side windows as well. This adds safety and sound insulation. Downside is that it cost more, weighs more, and more likely to show distortion.