Original link: JetBrains stops own IDE plans: Kotlin multiplatform development in focus / Heise Online.
Fact: JetBrains is pushing IntelliJ instead of Fleet for Kotlin multi platform development.
Speculation: JetBrains has lost faith in the Fleet product. That seems to be the obvious explanation for the decision.
JetBrains Fleet is a JetBrains product in the same space as VS Code and Eclipse Theia.