Merge pull request #257268 from paolamvhz/conceptualDocsUpt

Update room-concept.md for public preview in PSTN

Author: prmerger-automator[bot]

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

@@ -20,7 +20,7 @@ Here are the main scenarios where rooms are useful:
 - **Rooms enable scheduled communication experience.** Rooms help service platforms deliver meeting-style experiences while still being suitably generic for a wide variety of industry applications. Services can schedule and manage rooms for patients seeking medical advice, financial planners working with clients, and lawyers providing legal services.
 - **Rooms enable an invite-only experience.** Rooms allow your services to control which users can join the room for a virtual appointment with doctors or financial consultants. This will allow only a subset of users with assigned Communication Services identities to join a room call.
 - **Rooms enable structured communications through roles and permissions.** Rooms allow developers to assign predefined roles to users to exercise a higher degree of control and structure in communication. Ensure only presenters can speak and share content in a large meeting or in a virtual conference.
-- **Add PSTN participants.** Invite public switched telephone network (PSTN) participants to a call using a number purchased through your subscription or via Azure direct routing to your Session Border Controller (SBC).
+- **Add PSTN participants. (Currently in [public preview](https://azure.microsoft.com/support/legal/preview-supplemental-terms/))** Invite public switched telephone network (PSTN) participants to a call using a number purchased through your subscription or via Azure direct routing to your Session Border Controller (SBC).
 
 ## When to use rooms
 
@@ -116,10 +116,12 @@ The tables below provide detailed capabilities mapped to the roles. At a high le
 | - Render a video in multiple places (local camera or remote stream) | ✔️ | ✔️ | ✔️ <br>(Only Remote)</br> |
 | - Set/Update video scaling mode | ✔️ | ✔️ | ✔️ <br>(Only Remote)</br> |
 | - Render remote video stream | ✔️ | ✔️ | ✔️ |
-| **Add PSTN participants** | | |
-| - Call participants using phone calls | ✔️ | ❌ | ❌ |
+| **Add PSTN participants** **| | |
+| - Call participants using phone calls | ✔️** | ❌ | ❌ |
 
-*) Only available on the web calling SDK. Not available on iOS and Android calling SDKs
+\* Only available on the web calling SDK. Not available on iOS and Android calling SDKs
+
+** Currently in [public preview](https://azure.microsoft.com/support/legal/preview-supplemental-terms/).
 
 ## Event handling