I'm using this one: https://www.amazon.com/Mechanical-Practice-Exam-Questions-Solutions-ebook/dp/B08W1GTP9W/ref=sr_1_5?dchild=1&keywords=m.+rashad+islam+fe+mechanical+practice+exam&qid=1627603978&sr=8-5
says it's updated for 2021 but yeah you're right the author might have just forgotten to remove it. thanks!