Unfortunately you are partially wrong.
Uncover Treasure was updated few months ago. I even made post about it what i have noticed it Here.
There is even epic heroes there. 

As for login roulette i think it was also changed but much earlier than that. I'm not paying that much attention to that event.

As you stated IGG has updated the rewards in many events, and I am sure that they will continue to do so but you should understand that this process does take time.  However if I were you I would not count on seeing this occur in the "next update", if it should occur then great, but on the other hand maybe not.