The buried important part:

"It’s absolutely crystal clear that there are benefits of protein to muscle growth and exercise response of active individuals," study author Dudley Lamming said in a statement. "But because most people are relatively sedentary, many people are likely consuming more protein than they actually need, which probably has negative health consequences."

[/me proceeds to have more protein and keep working out.]

Seems like “probably has negative health consequences” in the article is missing “ceteris paribus” (negative when remaining sedentary).