They're definitely going in the direction of the walled garden strategy, but it's not necessarily a bad thing. For the vast majority of users, computers are safer with walled gardens. For the more advanced users, developers can always offer their apps through a different distribution channel.
In the case of Windows in particular, it's a chance to leave the installation wizards, the registry and the DLL hell behind and use the packaged model that macOS adopted from the get go.