I don't understand why you're saying that - it's contrary to the nature of symbols and language. Symbols are a unit of meaning, so their usage dictates their meaning. If Pepe was used exclusively by the right, then it would be a right wing symbol. If it was used by various people, but was particularly popular with the right to express right wing ideologies as memes, even then it would still be a right wing symbol when used as such. Symbols very frequently have multiple meanings, sometimes where one is dominant.

Anyway, I'm not commenting on where I think reality lands, just on your comment.