My professor is not teaching his online course himself, but uses publicly available videos instead. Is this appropriate?

If your instructor is available for questions, comments and discussions, then you can learn a great deal this way, potentially.

I recommend that you try to do just that. If, after at least ten days of really trying, you have difficulties, or find yourself concerned that you may not be properly prepared for courses that build on the one you're currently taking, then I recommend that you reach out to a department administrator. Present it as a problem you are having, not as a problem your instructor is having. However, do lay out in as neutral a tone as possible, a description of the current course format, and if your instructor has been unresponsive to questions, do include that information. Draft the email and sleep on it. The next day be brutal and remove any trace of whining or complaining. Just state the problem as a problem you are having.

Hopefully you will not have a problem.

Happy studying!

Your question is stated as "is it an issue". In this form I believe the right answer is "no, there are no issues". In some fundamental subjects like calculus or linear algebra I don't even expect for an average teacher to prepare "own" materials that would be different from more or less standard textbooks (after all, this is the purpose of textbooks -- to serve as standard teaching/learning materials). Next, I don't see any principal differences between "a textbook" and "a coursera course".

I understand you might dislike this way of organizing a course, but that's a completely different matter. At the end of the day I think you should be more concerned with acquiring appropriate knowledge rather than pondering on teachers' attitude. I believe Coursera provides decent content, so you should be happy (given that your submissions are properly evaluated and graded, and you receive appropriate guidance and feedback).

What you've described sounds like a very standard online class. The only thing missing is some kind of method for direct communication with the professor. Usually this would be accomplished through discussion boards although there are other options, e.g. live sessions via Zoom or WebEx. If the professor has included something like that to allow you to ask questions and get immediate feedback then I don't see anything out of the ordinary here.