VLC for Roku or I'll never buy a Roku product.
Roku only is responsible for the OS, The Roku Channel, and the Roku Media player. If you want 3rd party apps, then you need to contact them to write something for Roku.
If you already have VLC on a laptop, use a HDMI cable to your TV and you won't have to buy a Roku device.
A VLC channel/app designed for the Roku platform would likely have to disable some of their features/capabilities in order to be approved/suitable for use on Roku.