project.assets.json doesn't actually indicate which analyzer references a project should use.

Unlike "compile" and "runtime", the SDK is just pattern matching on all files in the package to find analyzers: https://github.com/dotnet/sdk/blob/634680ab0ae045ba45977b6293b46f95a0385aac/src/Tasks/Microsoft.NET.Build.Tasks/ResolvePackageDependencies.cs#L251

"analyzer" assets should work like "compile" and "runtime" and the SDK should resolve them the same way. The current mechanism blocks respecting PrivateAssets and ExcludeAssets=analyzers

cc @emgarten