[coldtea]

>Do you have any evidence for that claim?

No, but you can check it empirically and statistically.

>All the vegans I know use this definition.

Well, I know several people that self-identify as vegan (annoyingly so), who have no idea about the origins and just seen a few videos or read some articles and were convinced to try that diet.

(And of course they don't belong to any society either).

>Also, the vegan society was started in the 20th century.

Yes, confused it with the vegetarian society.