Answer:
True.
Step-by-step explanation:
Hard question.
I wouldn't say that he did any more than develop something other people used more extensively. Ella Fitzgerald was noted for scat; she used it almost all the time in the 50s and 60s.
Louis made the genre well knows by one song which he recorded in the mid 20s. (1926 -- Heebee Jeebees). But I don't think he was generally known for Scat.
As a developer: True
As a general user: False.
I think though you are intended to say that it is true.