I really like the noodles food comparison - it is a shorter label than the full definition. I see the term bonsai as taking on that broader definition as an “artistic woody plant that is not growing in the ground”. By itself it implies the Japanese variation, but as the craft/art evolves we will add adjectives to further define particular versions. Perhaps the flat top bald cypress and similar trees will become known as Cajun bonsai.
The terms adopted from other languages/cultures are often more succinct than the full definition. For example, pasta is a type of noodle that can take on many different forms - I like the use of penne pasta as opposed to “mid-length tubes of an egg-flour dough”. Nebari is encompasses the transition from the trunk to the roots as they enter the soil in a far shorter word than a full description.