Please have a look at this youtube video:prorender RTS Reality Server - Unreal Engine Pixel Streaming multiple clients on one GPU / the Cloud - YouTube
It shows the basic function for an independent multi client application with the Pixel Streaming technology. There are shown 8x independent Nvenc streams which are started only on one GPU server. In the video description there is further information that also larger cloud infrastructures can be realized, which enables an automated scaling for simultaneous client requests.
So your using scenario is possible if you use for each user an own Pixel Streaming connection and simultaneously creating a multi gaming application. The effort to develop such an implementation (multi-client, multi-gaming, auto scaling cloud infrastructure for Pixel Streaming) is complex but solvable.