Nope. The “speed of sound” is based on the speed it travels under a very specific set of circumstances.
This is known as a “standard” or “reference”. It can be different under different circumstances, but there is only one “standard”. And it’s not based on a common cruising altitude of a passenger jet.
This is what I’m talking about. You think you are smart because you learn a fact, but fail to understand the fact fully, and then try to argue. And in the process prove you don’t know much.
To simply say “the speed of sound is 660MPH” is wrong, because it doesn’t provide the parameters necessary for the number to mean anything.
It’s like saying “cruising altitude is 35,000 feet”. It is? Of WHAT, and WHERE?