Here is my experience getting my C18 in Mauve Sylvestre PHW.
I went to the store on Paseo de Gracia about 10 days ago. I asked for a mini Constance or Roulis. They had no Roulis but actually had a mini Constance in stock. It was crocodile leather in brown. I turned it down. The SA was very nice and asked if I wanted to create a wish list. I wanted a C18. My dream color would be pink, but I would be happy with neutral colors.
I told the SA I am staying in town a few weeks and she seemed quite confident and said there is a good chance. (Meanwhile, she said Roulis is not a wishlist bag, and it is actually harder to get one these days)
I never heard from the SA, but decided to drop by the store today to see other items. She saw me and recognized me immediately! She said she would "go check the stock", which I thought was just a formality, until she came up with a box!
She managed my expectation to say "it is something", and then it was a pink C18! Exactly what I wanted!
She said she couldn't get me sakura of bubblegum but Mauve Sylvestre is a new color. I was so excited she probably thought I was crazy

Overall a super pleasant experience. Of course I then asked to put a Birkin for my next wishlist item (And she said it is much harder because the list is long), so fingers crossed!