As they explained it, the turquoise/lapis is not discontinued. In December there was one pendant necklace available in Asia but it sold . . . There were no others in the company, and they wouldn't make another.
I assume it has to do with the availability of the materials--the lapis and turquoise are difficult to source whereas the gold, onyx, MOP, chrysoprase and carnelian appearing in the other Bouton d'or pieces don't pose the same issues.
I believe the other pieces in the collection are available, but I don't know for how long. I was told there are no bracelets in my size in the US, but one could be ordered so it's available--I just have to wait. I don't know about other pieces.
However, it seems that so many of these collections are available for a limited period and are then are phased out. For example, remember the Perlee hoops? Remember the perlee hoops with diamonds? All gone. The same too with the large Zodiac pendants. On the other hand, popular lines such as Alhambra, which is obviously a strong seller, remain active, whereas the more unique pieces seem to have a shorter lifespan.