Population growth by birth and immigration in the US has slowed and has been slowing for a long time now. I would be surprised if this had no effect on the labor pool and yet the article doesn't mention it.
The nation's immigrant population (legal and illegal) hit a record 43.7 million in July 2016, an increase of half a million since 2015, 3.8 million since 2010, and 12.6 million since 2000.
As a share of the U.S. population, immigrants (legal and illegal) comprised 13.5 percent, or one out of eight U.S. residents in 2016, the highest percentage in 106 years. As recently as 1980, just one out of 16 residents was foreign-born.
We simply have a larger share of the population that is too old to work, when compared to previous decades.
We’re entering a new era: expect more unions, more livable wages, a lessened quality of life on average, and above all - a higher level of inflation than the last 40 years. There will be winners and losers. If you’re a worker you will be fine, but make sure to take care of your parents.
Also, be sure to keep your parents from voting to secure access to the value created by your labor. Expect to see tons of measures to freeze property taxes, add price controls, and expand exclusive senior benefits they will kick and scream for to keep their purchasing power high at the expense of anyone capable of having a child.