Mesenchymal tissue can also undergo metaplasia.
A classic example is myositis ossificansmin which connective tissue within muscle changes to bone during healing after trauma - Pathoma Ch 1 pg 2
"Myositis ossificans usually occurs where a person has experienced a single traumatic injury, such as sustaining a hit while playing football or soccer that causes a deep muscle bruise.
It can also happen when there is a repetitive injury to the same area, such as in the thighs of horseback riders. Very rarely, myositis ossificans can occur after a severe muscle strain."