What's happened in the US at least since the recession is that almost all job gains have gone to those over age 40. The real agenda of this article is to discourage hiring workers over 40 in favor of younger workers. As to why employers favor older workers, it's because they are more experienced and also willing to keep working because they don't have enough savings to retire. This is an attempt to force employers to train younger workers even though already-trained older workers are willing to work the same jobs. Whether that's a good thing or bad thing depends mostly on your age and politics.

exactly... that's how the age discrimination will start again

Or maybe, not every field experiences ageism from the same end to the same degree.

Not even in our very ageist software industry is this consistent, if you take a look at things like mobile or web development when compared to lower level or legacy stuff.