Is a degree, or at a minimal, chemistry studies a necessity for a person that wishes to make natural perfume? No.
Some individuals are more talented at creating blends than others, however, making a masterpiece normally happens after years and years of experience.
In my opinion, if a person is going to delve into natural perfume, or any type of essential oil usage, a base knowledge of essential oils is needed. Why? For health and safety reasons. It goes back to the fact that just because something is natural does not mean it is safe.
The natural perfume goal is to create a blend that is pleasant and safe for the wearer. A 3-day class, or a 3-hour class, can result in a good perfume. It can, but does not generally result in a perfume that receives accolades around the world.
Why did I bring all of this forward? Opinions are treasured, trust me. But I will stick to my guns that a degree is not needed to be creative.