Support of .NET Standard 2.0 in v4.x?

[nightroman]

The README says:

Orleans is compatible with .NET Standard 2.0 and above, running on Windows, Linux, and macOS, in full .NET Framework or .NET Core.

But the preview package versions v4 do not seem to have netstandard2.0 in dependencies. Is this just preview or does it mean the end of .NET Standard 2.0 support?

(This might be fair and reasonable for servers but rather sad news for clients, e.g. some .NET Framework based)