As it is known, Phantom Liberty was the first and only DLC for the action/RPG Cyberpunk 2077 by CD Projekt, which is actually atypical for such large and expensive games. As it turned out, another DLC was planned for Cyberpunk 2077, which was supposed to take place on the Moon. Insider Gaming writes about it in a report.
We are talking about the evidence of the existence of such DLC that has appeared on the Internet. These include images, concept art, diagrams, file collections, and mapping data. The moon plays an important role in the game's lore, for example, the colony on the Earth's satellite is mentioned both in the Phantom Liberty expansion and in the anime Cyberpunk: Edgerunners. In the Cyberpunk 2077 universe, the Moon has been colonized, has several cities, and is important for corporations. At the time of the game's events, about 58,000 people live on the Moon.
It seems that at the beginning CD Projekt was planning to make the Moon the main setting of the base game, but later they decided to return to Earth and move the Moon to the DLC, which, in the end, was never released. It's a shame, because a DLC outside of Knight City would have been a very interesting change of environment for the player.
As you know, CD Projekt is currently working on the sequel to Cyberpunk 2077 and calls the first game "just a warm-up" for this project. Well, maybe we have a chance to see the Moon in the conventional Cyberpunk 2. But it will most likely be no earlier than 2026. Realistically, in 2027-28.