Yes; but still, I don't wish to be accused of opening Pandora's box. If you examine American Yamidori trees they still have many of the refinements and traits that make and refine classic bonsai forms. You still have approved and disapproved branch placement, specifically bar branches, branches at the inside of curves and all of the other basic things that tend to scream out at you for violating. The formation of foliage pads, the use of triangles etc, these are the basic elements of the internal combustion engine of the bonsai art that seldom change enough to cause the community to rethink their sensibilities.
Yes, the classic styles were originally Yamadori trees but; much of the way they were styled was from what could be called Surreal representation of a quasi spiritual ideal of how things should be, not always how things actually are. As I mentioned earlier Yamadori trees; seem to march to their own drummers and tend to make the rules rather than follow them.
This is a fact. If we assume that there is a book of rules that can and should be followed then we must assume they had to be defined somehow, somewhere, and sometime. How did this happen? I have said this many time before: Rules are those things that define what some master did sometime ago to achieve success.
What was done then seemed to define what others observed as being the things necessary to define a bonsai----a rule. So the ubiquitous bonsai growers seeking to emulate that success did the same thing ---- they followed a rule. In short: Art defines the rules and what they are if, enough people admire that art and seek to emulate it.
If additional art comes along and more people seek to emulate that as well then; that art defines a new set of rules that my replace the old rules or redefine them. Please understand this: Rules are for the breaking if you can get away with it by doing it so beautifully as to stimulate others to follow, and do the same--- now we have a new rule. If your art or your impression of the art is significant enough to be studied and coppied by others then you too can make the rules.
I must have serious "bonsai' OCD...haha.. hate to admit it, but I think I've watched every Ryan Neil youtube video more than once! 
