Very true, although the lack of older coders isn’t in itself proof of ageism. The candidates for tech jobs already skew younger for a variety of reasons, from the relatively recent explosion of computer education to the rapid pace of change (which can make legacy experience less valuable). There really are more young applicants for tech positions and programmer jobs.
But the Visier study compares the ratio of applications to hires at different age groups, to show that tech companies prefer to hire younger people overall — although even their bias seems to be less than we expect. That said, it’s no comfort for any senior developer who’s passed over because of their age and (anecdotally) it’s a reason why some move to contracting work later in their careers.