ETF companies are primarily for-profit companies so they will most likely choose the network that they believe will give them the greatest profits in the event of a hard fork.

This means that they will most likely choose the network in which the price is higher or the number of investors is greater. As for ETF investors, they do not have the right to object or choose the network that suits them because in reality they do not own Bitcoin, but rather own shares in these companies, and therefore they are forced to accept the choice of networks that the companies choose.

Then investors will face great risks because if companies choose one of the networks and it becomes worthless over time, this means that investors have lost their money.