The Pirate Hideouts nodes no longer appear in the H.E.L.M. and the seasonal quest can no longer be progressed. This is most likely a bug that is affecting all Plunder quests as the Star Chart also no longer offers bounties and has also been removed from the bounty vendors list in the Destiny 2 Companion app. Season of the Risen and Season of the Haunted did not have their bounties removed and can still be accessed from the companion app.