Hi! I manage Kubernetes Academy. We are not affiliated with the CKA Exam, and have no expectation for people to take it. Our team has received questions on how to best prepare for the exam, so we created a prep course. No strings attached.
In my opinion, if you are honestly looking to educate, and it is not just a marketing, then look into delivering the education that is better than anyone else.
As someone who just started working at a company that is converting from VMware to Kubernetes but who has zero experience with it and only a little with Docker, this seems like a good start. Of course I have about 20 other tabs in my browser for learning.