You can technically get it to run, but due to the inherent forwarding / relaying of audio and video between the local computer(s) and the RDP server both ways - there are many issues that will often cause large delays and breaking up of the audio and video. This is not and RC app issue, but this occurs with all audio/video apps used in the RDP setups.
We do use the RC apps on our own RDP setups, but only to monitor call logs, and messages, not to actually do any live audio or video connections.
Technically you can make this more reliable and working fairly well if you want to invest in high-end video/audio equipment on the RDP server, ensure you have full GB speed connections between your workstations and the server, and the video / audio equip on the workstation(s) is high quality (as in built-in compression chips for speed, etc.). We use RDP for the purpose of not wanting to worry about the client workstations age, type, or quality - so this defeats the purpose we use RDP for, so we don't use it.
We tried this a while back. We use RDS with as many as 20-30 people at a time on a box. The issue we ran into is that you can only have one instance running. So if User A launches it. All other users cant. Which makes it pretty useless on RDS.