Thanks to @Dystroph on Twitter for pointing out this upcoming Japanese delisting. Bandai NAMCO announced last February that Pro Yakyuu Famista Evolution and all of its downloadable content would be removed from sale on February 28th, 2019. No reason was given but with the names, mascots, and likenesses of Japan’s baseball teams (and even a cross promotion with New Japan Pro Wrestling) it seems most likely that it’s related to expired licensing.
For those interested there is a physical version available though it’s also a Japanese exclusive and doesn’t include the DLC teams. The date has been added to the Watch List calendar.