It looks like gathering the 10 Knowledge to unlock the legacy trait and choosing the trait from the event pop-up does nothing.

The knowledge gathering was also rather slow, with the map tiles with knowledge being much much rarer than the abundant food. 

While not explained, so unsure if intended or not, it seems like sacking sanctuaries also gives knowledge as at 9/10 I had sacked one and got the event for legacy choice the next turn with 10/10, event which when mousing over the choices did not explain what each choice would net me, nor does it seem like it had any effect.

I have the exact same issue of not receiving my legacy trait in the Neolithic Era, no matter which one i pick.

Hi! Thanks for your reports. The Neolithic Legacy trait is not yet displayed in the Empire screen once unlocked, but its effect should apply to your empire.

That is great to know, any way of checking what the Neolithic Legacy does? The event does't say what bonuses you get for each choice. What effect will choosing Makers have now that I'm in Ancient Era.