To clarify, it's using React Native XAML, where XAML is Microsoft tech for building UIs. So they are dogfooding but they have too many UI frameworks to choose from.
You wouldn’t use MAUI to build something for only one platform. You would just use whatever it’s an abstraction over for that platform which in the case of Windows is WinUI.
.NET Maui running on windows seems like a more logical first step to prove the organization buys their own dogfood.