Why is a “bindingRedirect” added to the app.config file after adding the Microsoft.Bcl.Async package?

The assemblies Microsoft.Threading.Tasks and Microsoft.Threading.Tasks.Extensions are still referencing v1.5.11.0 of System.Runtime and System.Threading.Tasks.

Without the bindingRedirect, the Microsoft.* assemblies would try to load an old version of the System.* assemblies, which would fail.