Update howto-connect-vnet-hub-powershell.md

Author: stegag

articles/virtual-wan/howto-connect-vnet-hub-powershell.md

@@ -18,6 +18,9 @@ This article helps you connect your virtual network to your virtual hub using Po
 > * A virtual network can only be connected to one virtual hub at a time.
 > * In order to connect it to a virtual hub, the remote virtual network can't have a gateway.
 
+> [!IMPORTANT]
+> If VPN gateways are present in the virtual hub, this operation can cause disconnection to point-to-site clients as well as reconnection of site-to-site tunnels and BGP sessions.
+
 ## Prerequisites
 
 * Verify that you have an Azure subscription. If you don't already have an Azure subscription, you can activate your [MSDN subscriber benefits](https://azure.microsoft.com/pricing/member-offers/msdn-benefits-details) or sign up for a [free account](https://azure.microsoft.com/pricing/free-trial).
@@ -50,4 +53,4 @@ This article helps you connect your virtual network to your virtual hub using Po
 
 ## Next steps
 
-For more information about Virtual WAN, see the [Virtual WAN FAQ](virtual-wan-faq.md).
+For more information about Virtual WAN, see the [Virtual WAN FAQ](virtual-wan-faq.md).