even if it is a stunt, the price of Bitcoin Cash got up to 900 USD, it is trading in futures right now and miners are signing on to mine it. it is going to be listed on a few places.
I mean the best thing to do is to have your BTC in your own walleet you have access to the private keys. If a split really does happen you can have both coins anyway.
say you have 1 BTC, coin splits, you now have 1 BTC and 1 of the new coin. But only if you have access to your private keys(bitcoin core wallet and others let you do that). You have to use a command(which someone will make a guide to I am sure) and it will let you claim your other coins. Similar to how Clams were claimed.