The answer is: it depends. Some newly formed departments are bad (unorganized, little funding, etc.) While others are excellent.
I am in a newly formed department Ph.D program (~5 years old) and it is still very unorganized. They still don't know what works the best for students and are basically "testing" different rules and regulations out each year. But more importantly, I would look into specific professors that you are interested in working with and contact them. Then based your decisions on that.