• In a job description from November 2024, the Scratch Foundation said
  

  In 2025, we're responding to this growth by focusing on three strategic priorities: developing the new Scratch 4.0 …

  This was the first official mention of 4.0.
  
• In another job description, they said

  As we approach our 20th anniversary in 2027, Scratch is entering a new era. We are
  launching Scratch 4.0

• In Scratch's 2024 financial report, Margaret Honey, CEO of the Scratch Foundation, said
  

  As we look ahead to Scratch 4.0 and our ambitious goal to reach the next 100 million children by 2027

• Also in the report, Mitchel Resnick, founder of the Scratch foundation and one of the people who created Scratch, said
  

  We are now developing a new generation of Scratch, called Scratch 4.0, that integrates generative AI into the Scratch platform in ways that will support (not replace) young people’s creativity.

• The report also says
  

  Scratch is on a mission to reach 100 million more young people by 2027. This bold, $30M initiative will fuel the creation of Scratch 4.0, help us amplify youth voices around the world, lay the groundwork for a sustainable future, and ensure that the Scratch platform remains free so that every child, everywhere, can create what they imagine.

• Images like this were circulating online recently; based on my own research, I believe they are real leaks.
  
• Most recently, the Scratch foundation released a video asking for donations to fund Scratch 4.0 and their 100 Million More campaign.
  

DeathReviews wrote:

(#4)
Nope, no AI. They canceled it. If i had to guess, I think it would be out in May, next year.