I'm sure there is ageism from younger devs, but be sure not to confuse it with respect. In my experience, younger devs (like me at the time) were always excited to learn from older devs.
Interesting thought though, what if the product in question is a product geared toward a younger audience that younger devs are more "in tune" with? Assuming they have more impact as a result.
They shouldn't be expected to compensate for their lack of youth in any way, as youth isn't a metric that has any relevance to their work in software development. And if they are of the same title/total comp as the young dev, there is nothing wrong with them being on par in terms of skills/knowledge/responsibilities.