It's probably better to say that the PPK/S .22 currently is in production again. Production was discontinued in 2014 and resumed three years later. There are no 2015 (BF) and 2016 (BG) models.P.S....
In the event that it has escaped notice...this thread was begun nearly FOUR(4) years ago, in April **2016**.
It's now January 2020 and the UMAREX/WALTHER PPK/S .22 is STILL in production.
At the beginning of 2016 I was convinced that the production would continue in the U.S. (https://www.waltherforums.com/forum/ppk-s-22lr-new-production-umarex-2013-later/47128-product-page-listing-ppk-s-22lr-has-vanished-carl-walther-de.html#post470685). I was wrong obviously. But I wouldn't be too surprised if it will happen sooner or later.