There is potentially a lot of money to be made in setting up alternate tech solutions for the people being deplatformed. The question is, how to monetize such solutions? Not sure if it would be realistic to expect substantial revenue from advertising. On the other hand, a subscription model would need some sort of payment processing and potentially would create privacy issues. But maybe these problems can be solved with enough ingenuity. I guess it's also possible that one could set up a social network with very large capacity just by relying on donations from rich sympathizers.