The statements made by Nike are commercial speech. The speaker is a company engaged in commerce sending messages to an audience of actual or potential customers of athletic apparel. The statements were designed to encourage people to buy Nike products.
The statements can be regulated, even if they are related to labor disputes and not the actual sale of products or services.
The California law does not suppress the expression of points of view or ideas. The law regulates misrepresentations of fact.
There is no evidence or cases that show that California’s law deters companies from speaking out concerning social issues or other areas of protected speech.