That document can absolutely be interpreted to say that this is blatantly illegal, but it doesn't explicitly address the question of maximum years of experience, so it's a matter of interpretation. Have they explicitly addressed this question somewhere else?

https://news.bloomberglaw.com/daily-labor-report/insight-cap... is a more recent article summarizing a court ruling from the Seventh Circuit Court of Appeals in which, at least for the states covered by that court, it was determined that job applicants (as opposed to transfer or promotion applicants) can't bring disparate impact ADEA claims against theoretically age-neutral rules such as maximum years of experience. State or local age discrimination laws can go beyond the ADEA, of course, and some do.

I wanted to chime in the the military part. This is not an age limit on positions to keep old people out, this is to weed out under performers at a time where the military has a glut of highly qualified volunteers.

So up or out means “if you’re passed over for promotion twice, you must suck and we don’t want you anymore.”

But I have seen old officers in the lower ranks because they were enlisted men, then warrant officers, then finally officers. They were far older than their peers, but still needed to tick the boxes and get promoted.

Ref: Military Officer