Of course you can change them. You can’t influence what AI on the Edge does, but you can publish payloads to those topics whenever you wish, via whatever your favorite method is. For example: from within MQTT Explorer, or using HA’s MQTT.publish action, or using mosquitto_pub from the command line, etc.
My suggestion was, if you want to debug further, you’ll need to remove the default_entity_id from the payload, get the deprecation notice again (reload MQTT or restart HA if necessary), clear your logs, and then add it back in again, and see if the deprecation notice comes back. As long as your ESP cam doesn’t reboot during this debugging process it won’t affect anything.
On a normally functioning installation, adding the default_entity_id to the autodiscovery payload of an existing entity is all that is needed. You don’t need to delete and recreate the entity. HA will recognize the addition and will stop issuing the deprecation notice in the logs.