Just my presonal feedback.

The initial presents were good and made we want to play Raid more.

However, there is nothing exciting about the whole anniversary events. They are just the same stuff you do every day, every weeks. 

Just by sticking a page somewhere, on which you can see that the usual path or dungeon run is now labeled as anniversary event does not make it exciting.

There could have been many more interesting events...

like: 

Hey, it is our anniversary and we want to say thank you. We have a Legendary event in which for the first legendary champ you draw, you will get the opportuntiy to choose among six possible champs (okay, stole this idea from Jgiggs).

You could have made events like Run this or this dungeon on Auto and achieve the exact time of 2 mins 22 seconds (adding the numbers results in 6) and you get a leggo book as reward.

Your 666th ancient shard you pull over the course of the anniversary event is an automatic leggo from the demonspawns.

Level up 6 heroes to lvl 6 to get a feast

Run 6 dungeons (min lvl 20)-> Spider, Dragon, Fire Knight, Ice Golem, Sand devil and Shogun within 12 minutes to get 6 energy potions.

There are plenty of opportunities to make an Anniversary fun for your players also....

But this Anniversary event does not feel like different from the usual game play. Not exciting...