If there will be network split, many will dump all their free BTU when it get listed which will just pump the real BTC to the moon.
BTU will be another dead cow instantly after getting listed as just another altcoin

How can you say that? The hard fork can't happen if Bitcoin Unlimited doesn't get at least 75% of the total hash power. And if it does there's only a possibility of a split if the supporters of Core continue mining their chain and become the minority.
So how can one say that BU has no value and should be dumped if it has the majority of hash power?