If you're suggesting based on your workplace that young people are more likely to find jobs overall, you are incorrect.
"On average between 1989 and 2007, the unemployment rate of workers under age 25 was 2.2 times as high as the overall unemployment rate. [...] In March 2015, the overall unemployment rate was 5.5 percent, and the unemployment rate of workers under age 25, at 12.3 percent, was 2.2 times as high."
He didn't say anyone is ageist against millenials. He just said millenials are not the ones who are ageist. I think this is probably still not true, but it's the claim.