It might not be true for the whole workforce, but it is true for the median. For the rich healthcare costs make up basically nothing in their compensation, so all of their compensation increase show up as higher wages. The really poor often don't get healthcare. But for the median, they get healthcare and healthcare expenses are fairly big compared to their wages.

This doesn't mean that the compensation of the median worker has perfectly tracked GDP growth, because there has been a moderate but genuine increase in inequality in compensation. But it isn't nearly as big as the increase in the wage gap, and saying "real median wages have decreased" is misleading.