Update room-concept.md

Author: allchiang-msft

articles/communication-services/concepts/rooms/room-concept.md

@@ -100,7 +100,7 @@ The tables below provide detailed capabilities mapped to the roles. At a high le
 | **Mid call controls** | | |
 | - Turn video on/off | ✔️ | ✔️ | ❌ |
 | - Mute/Unmute mic | ✔️ | ✔️ | ❌ |
-| - Mute remote user | ✔️ <br>public preview</br> | ❌ | ❌ |
+| - Mute remote user | ✔️ ** | ❌ | ❌ |
 | - Switch between cameras | ✔️ | ✔️ | ❌ |
 | - Active speaker | ✔️ | ✔️ | ✔️ |
 | - Choose speaker for calls | ✔️ | ✔️ | ✔️ |
@@ -136,6 +136,8 @@ The tables below provide detailed capabilities mapped to the roles. At a high le
 
 \* Only available on the web calling SDK. Not available on iOS and Android calling SDKs
 
+** Currently in [public preview](https://azure.microsoft.com/en-us/support/legal/preview-supplemental-terms/).
+
 ## Event handling
 
 [Voice and video calling events](../../../event-grid/communication-services-voice-video-events.md) published via [Event Grid](../../../event-grid/event-schema-communication-services.md) are annotated with room call information.