Basic comprehension. "In doubt" doesn't mean "thinks you are wrong" but simply isn't convinced that you are right
Nope you made an active claim. One remains agnostic "in doubt" , any opinion you adopt you must provide proof for. In this case one remains agnostic if all styles can be imitated or not. But you don't , you hold an opinion which is "all styles can be adopted " therefore you are required to provide proof.
Also your claim is not a negative claim , since there is no negation in your statement.
The negative claim is actually the opposed opinion which is "not all styles can be imitated".
So please provide proof for your claim.
The fallacy is shifting the burden of proof/appeal to ignorance.