You supply the ages with the software and AI uses that just like you would.

If it doesn't know the month, it puts it in June. If it doesn't know the day, it puts it on the 15th. But yeah, old photos with EXIF is more to be used by putting them in an order of photo1 comes after photo2, etc. Not necessarily photo1 is exactly 1982, etc. Viewing and enjoying old family photos is more about the order, and less about the exact year (at least for my family and friends).