The same way coding agents don’t replace the need for an IDE, content generation needs to support arbitrary human-to-agent handoffs, where the human can say “this is the wrong direction, I sketched this change of what I want it to look like, see how it’s different and apply that pattern.”

And, in the broadest sense, that human interface is a CMS; the agent is just another editor, albeit one that happens to read and write raw data rather than using a WYSIWIG (or similar) editor.