According to Treyarch's director of development, Call of Duty: Black Ops III is going to have an updated version of game's editor. While the developer didn't specify the exact time of the release, he said that the alpha testing of Modtools is around the corner. Here is his statement:
"Last time we released our map editor was CoD: WaW. It has changed a lot in 8 years. Modtools closed alpha is right around the corner. #8^B"
You can check the developer's Twitter account and the statement here.