If a chainsplit happens and persists the price of the original token would likely split between the two takens, not by any protocol rule but because of the free market. The capital is splitting between the two. So in a sense you aren't getting a free air drop, the total value of both chain will probably equal the total value of the original. There is still a lot we don't know about how the market reacts so for now a lot of this is just hypothetical.