I am not convinced this is the "skill of the future" for designers to master. I can't help but think this is akin to teaching telegraphers how to effectively write morse code, back when electrical telegraphs were the "hot new tech" in the 1840s. Prompt writing might help you today, but is this really the future of UX design? More crucially, is this the future that YOU as a designer really want? Learning how to effectively encode instructions for a machine that you don't own or control?

I think the big opportunity is actually teaching UX designers how to design and prototype predictive ML models. A designer should be able to "mock up" an ML predictive model (understanding bias, ethics, algorithm patterns, user experience, etc.) as easily as one can mock up a web site today. These are not coding skills, but understanding the human side of what inputs are needed and what people will do with the decisions that your prototype spits out.