No, tradition is not merely oral communication.
When I relate an event that happened to me yesterday to someone, that does not make it a tradition.
Please note definition #2
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tra·di·tion
noun \trə-ˈdi-shən\
: a way of thinking, behaving, or doing something that has been used by the people in a particular group, family, society, etc., for a long time
: the stories, beliefs, etc., that have been part of the culture of a group of people for a long time
—used to say that someone has qualities which are like the qualities of another well-known person or group of people from the past
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Full Definition of TRADITION
1
a : an inherited, established, or customary pattern of thought, action, or behavior (as a religious practice or a social custom)
b : a belief or story or a body of beliefs or stories relating to the past that are commonly accepted as historical though not verifiable
2
: the handing down of information, beliefs, and customs by word of mouth or by example from one generation to another without written instruction
3
: cultural continuity in social attitudes, customs, and institutions
4
: characteristic manner, method, or style <in the best liberal tradition>