Disabling matchmaking will not erase your data, meaning you can re-enable it at any time. Disabling it will only remove the matchmaking selection process from the event front-end when an attendee is joining the event.
How to disable matchmaking
Navigate to the 'Matchmaking' Settings from the event admin panel.
Toggle the button to disable matchmaking under 'Enable/Disable Matchmaking'
All done! You have now disabled matchmaking for your event successfully. You can enable it again by following the same steps.