Atlus confirms that the licensing has expired for both titles
If you were planning on getting some Utawarerumono games on Sony platforms, hopefully you already purchased and downloaded them. The PlayStation 4 and PS Vita versions of Utawarerumono: Mask of Deception and Utawarerumono: Mask of Truth have been delisted from the PlayStation Store in the west, and Atlus was quick to confirm their removal.
According to a followup with Gematsu, the titles were delisted from the PlayStation Store due to the expiration of the rights in the west. As for whether or not they'll ever reappear, there's currently no information on the matter.
Both games are still available on PC via Steam, where they're published by DMM Games and Shiravune.