To prevent Kolide from automatically enrolling your device, you first need to uninstall.
When you're switching devices, you might want to unenroll your previously used device from the naisdevice ecosystem. This procedure is currently a manual operation done by one of the assigned admins within the Nav organization at Kolide. The list of admins is available for viewing at k2.kolide.com (sign in with your Slack account), under Who can access my data?
Messaging one of them with a request to remove the particular model you wish to unenroll should be sufficient to start the process. You can also ask in the #naisdevice channel on Slack - the admins of NAV's Kolide integrations can be reached there.
Don't share your device's serial number publicly
If you happen to switch devices to an identical model, it might be needed to supply the device's serial number to one of the admins in order to identify a specific device. This serial number should not be posted publicly, so ensure that you're only sharing it in DMs and not in any public channels.