I have no idea. But you can rest assured that if I'm not playing against a post-rotation deck, then I'll have to face a VS Seeker deck, which is quite a challenge in itself. I'm not as interested in the "current meta" opponent as I am in the opponent with the advantage of using older cards.
My point is, if you are not solely testing the post rotation Decidueye/Rare Candy theory against post rotation decks (BKT-BUR) then your testing is completely useless. The whole point to this thread is to find out if it can survive post rotation, but if you're not testing with a post rotation deck and against post rotation decks, then your results are incredibly flawed. You're basically playing a bad version of Decidueye, not Decidueye/Candy's relevance post rotation.
I understand completely, especially the part about "bad version of Decidueye". But my point is, if my opponent can use older cards and has an advantage over me, and I still win, then my deck has the durability to stand up against post-rotation decks as well as older decks. In other words, pre-rotation decks are much tougher opponents than post-rotation decks. I will eventually try out the same deck as a practice deck against some friends I have in the league (they are using post-rotation decks as well). Thank you for your suggestions.