Yes Umarex owns walther so they can call it a walther. Doesn't mean it is made it walthers factories, do a Google search on this subject. And judging by the performance of the pistol I would definitely think this is the case. It came from the factory printing 4 inches high and 2 inches to the right at 10 yards. Never saw that from any pistol I have owned in the past.
The .22LR PPQ is made by Umarex in Arnsberg, Germany (near Cologne) and has the "shield with three crowns" proofmark of the Cologne proofhouse. The PPQ (9mm and .40SW) is made by Walther in Ulm Germany, and carries the "staghorn" proofmark of the Ulm proofhouse.
Walther in Ulm has a reputation for producing very high-quality pistols like the P99, PPQ, and PPS.
Umarex... not so much. They primarily make airsoft toys, starter pistols, and lower-quality potmetal (Zamak) rimfires, such as the "Walther" P22, and a number of other licensed guns (including .22s marketed as HK, Colt, and S&W products). If the .22LR PPQ slide is an aluminum alloy, perhaps that is a move in a good direction for them, not the same quality as a real Walther pistol.