Well, I'm going to share my feedback on this new ancient event...
Saddly it wasn't good for me 
I only got the epic dragon from 1st chapter of dragon board, no new ancient, I was nearly ~300 for noloskol and 200 for the ancient of dragon board. 
Even if it didn't ended in a good way I was pretty happy of some things :
° The cost of the rolls (150 instead of 200)
° The cost of the reroll (25 instead of 50)
° The number of ancient chest needed to have the guaranted ancient
I think I forgot some but there was a lot of better things globally ! 
The only thing is that it was kinda short in my opinion + I had school so I missed A LOT of resests... 
I hope it'll improve on that side for people that can't play because of school/work etc...