It is a pretty typical clause. Especially for guys who are used to being paid as top of the rotation starters. To think he's just going to sit in AAA all year is kinda laughable tbh.
He's 33. He has a lengthy injury history, a slight frame and an uneven track record when healthy. If you think he's even remotely similar to Alex Cobb, I really don't know what to say. Cobb has been a 2 WAR pitcher every year that he's appeared in 10+ games. The majority of Buchholz's seasons have been worth less than 1 WAR.