I remember that these redesigned slides started showing up on PPQ pistols here, after the Taiwan Police awarded a contract to Walther for the PPQ. The picture of the contract pistol had changes from previous PPQ pistols. These changes then seemed to trickle into all of the production PPQ pistols.I believe they did it when they made the PPQ 45, then added the change(s) to the other PPQ variants.
It may have been to add strength to the slide. This is the one and only cracked PPQ slide that I've seen or heard of, and I mentioned in this thread that the redesign may have prevented this. I believe that it may have if the crack was to start at the top of the ejection port:There seems to be different contours to the ejection port on the PPQ. I assume mine has a old style even tho i just bought it brand new. Is there is a reason why they changed? Did the old style cause reliability issues?