Did Yahoo stop updating top contributes ?

Hard to say. The TC info is in each users profile now (no indication on their avatar as there used to be) and since many users post in the same 1 or few subcategories, they may keep the same TC "badge" for a long time. Unless you notice yourself or someone else with a badge and then it changes (a new one added or an old one drops off) no way to know if they are being "updated".

Awarding TC badges stopped some time  ago........and those that had them at that time,   basically still have them........frozen in time. 

Leaderboards, in each category,   *WERE* still working until  just fairly recently.   I know, because I am on a number of them.........but then they finally froze those too, and the numbers are no longer being updated. 

The main, overall Leaderboard........has been frozen for YEARS. 

The odd thing is..........personal point tallies.....still work. 

But the leaderboards simply don't reflect that. 

Years ago.