Т.к. новых новостей по поводу Blazor нет, то вот вам анонс первой превью версии .NET 5:
https://devblogs.microsoft.com/dotnet/announcing-net-5-0-preview-1/
https://devblogs.microsoft.com/dotnet/announcing-net-5-0-preview-1/
Microsoft News
Announcing .NET 5 Preview 1
At the end of last year, we shipped .NET Core 3.0 and 3.1. These versions added the desktop app models Windows Forms (WinForms) and WPF, ASP.NET Blazor for building single page applications and gRPC for cross-platform, contract-based messaging. We also added…