Playing online does not always require the same device to connect. Some games have been designed to allow a family with an Xbox to play with their friends with a Play Station etc.
It is helpful to know and learn about these types of options in advance as parents and as therapists to help look at which games allow for this option despite the use of a different platform. It is also important then to look at how the individuals will communicate with each other, whether its online through typing, through voice on headsets. In some cases individuals may prefer to simply talk on the phone at the same time as watching / playing the game as it suits their physical coordination and timing of how they interact with the game.