The concept doesn't lend itself to Linklater's typical style. It doesn't sound like it will be a hundred minutes of characters lecturing each other (erm, conversing).
It has already been done by Truffaut. His five film series The 400 Blows, Antoine and Colette, Stolen Kisses, Bed and Board and Love on The Run followed character (Antoine Doinel) and actor (Jean-Pierre Léaud) ages 14 through 34. Of course there were gaps between the films, but his growing up and aging was pretty well covered.
Ted