Yup.
Kickstart is intended to build the system up from scratch.
We check for API keys, users, and a few other things to ensure we can start with a clean slate.
If you already have an API key configured, you can also just script a set of API calls on your end as well. This is more/less what kickstart does.
From the Kickstart docs:
Kickstart will only run if no API keys, users or tenants exist, so you can safely leave this environment variable configured even after the system has been configured.