5. почитают остальные мнения команды Arduino:
- "Arduino language is merely a set of C/C++ functions"[1],
- "some minor pre-processing to turn your sketch into a C++ program"[2],
- "the code that you have written is translated into the C language (which is generally quite hard for a beginner to use)"[3],
- "Arduino API, aka the "Arduino Programming Language""[4]
6. посмотрят на анализ препроцессора[5] (такой же, но теперь не от меня) и решат для себя, имеет оно право называться новым языком или нет ("three lines away from being standard C++")

[1] https://support.arduino.cc/hc/en-us/articles/360018448219-Ca...
[2] https://arduino.github.io/arduino-cli/0.36/sketch-build-process
[3] https://www.academia.edu/33554986/Massimo_Banzi_Getting_Star...
[4] https://docs.arduino.cc/learn/starting-guide/getting-started...
[5] https://hackaday.com/2015/07/28/embed-with-elliot-there-is-n...