In 2019, the series creator, Ron Gilbert, tweeted a poll asking fans if they would be interested in a new Monkey Island game. The poll received an overwhelmingly positive response, with around 90% of respondents expressing interest.
In 2020, Gilbert revealed that he had pitched a new Monkey Island game to Lucasfilm Games. However, there haven't been any updates or announcements regarding the status of this pitch since then.
Furthermore, in April 2022, Devolver Digital, a video game publisher known for releasing indie titles, acquired Lucasfilm Games' back catalog of adventure games, including the Monkey Island series. While this acquisition sparked speculation about a potential new Monkey Island game, there hasn't been any concrete information shared by Devolver Digital or Lucasfilm Games.
It's worth mentioning that the Monkey Island franchise is owned by Disney, which now owns Lucasfilm. Therefore, any decisions about the development of a new Monkey Island game would ultimately be made by Disney Interactive.
To stay up-to-date with any official news regarding a potential Monkey Island 6, I recommend following the social media channels and websites of Ron Gilbert, Devolver Digital, and Lucasfilm Games.