Microsoft only has the resources on some of the core components and serves its primary customer base,
- .NET Core runtime
- C#/F# languages (VB.NET is phasing out, J# is dropped a few years ago)
- Frameworks like ASP.NET Core, WinForms, WPF, Blazor, and EF Core
It would be the responsibilities of third parties to fill the gaps and serve special needs like yours, and companies like RemObjects do enable Java applications to migrate to .NET runtime,