You are be able to make a messaging and appointment service called "Networking" available to participants of your event. However, if you do not want them to use the Appointment Scheduling feature, you can disable it. Here's how:
From the admin tool, go to the "APP" tab. Then click on "Interactivity" and finally "Networking".
Deselect the "Allow participants to set up meetings".
Click the "Save" button.