The locusts of Joel Chapter 2 no longer refer to Jehovah's Witnesses and events surrounding 1919.
The locusts in Revelation chapter 22 however still do refer to the anointed, but are now no longer connected with the prophecy on Joel.
Joel 2 now refers to the "Babylonians", the coalition of nations that will try to destroy God's people.
The context of Joel chapter 2 points the time period of fulfillment to Jehovah's Day in the Great Tribulation and how God will save his people.