You seem to have missed this e-mail from Mosaic:
While we try to always give our customers a reasonable lead time when a set is going out of print, sometimes circumstances beyond our control force us to delete sets on short notice. During the recent sale of EMI Music, pieces of the company were sold to Warner Bros. rather than Universal Music. As a result, we lost the rights to manufacture more of our Sarah Vaughan (Roulette) and Django Reinhardt (EMI France) sets. The supplies we have on both sets are very low and will only be available for a short time. We apologize for any inconvenience this may have caused.