Kadon that made the Scrolls of Binding definitely existed long before the Colleges were founded.
There is definitely at least 2 different Kadons- the one that founded Mourkhain and was killed by Ushoran, and the one that made the Scrolls of Binding.
That 2nd Kadon may-or-may not be the same Kadon that the Transformation of Kadon is named for.
There might be other Kadons too, hell if I know, name seems pretty popular. Pretty sure Boney said that there's a Kadon that was an Amber Supreme Patriarch.