Why are 1 Timothy, 2 Timothy, and Titus referred to as the “Pastoral Epistles”?
All three of those letters are written by Paul to people who he mentored in the faith and are now leaders of churches (pastors) in their own right. They also deal largely with instructions and advice relevant to church leaders - i.e. with 'pastoral' matters. That is why they are called Pastoral Epistles.
The name is not doctrinal matter - it is simply a convenient name for a group of similar letters. As such no denomination either enforces or rejects the label. People use the name if they want, and if it's convenient.