And Unity can continue to raise the per-installation price as well. If they lose a bunch of customers but want to maintain their current income, why not raise it to $1 instead of just $0.27?
What jurisdictions recognize this term and legally protect those who agree to them?
So if you've ever released a Unity game (even if it hasn't been updated in years), even if you delist your game from the store today, presumably you could still get charged if people who already own your game reinstall it.
I'm not a lawyer, but I really don't see how that'd hold up in court — you created a product under different terms years ago, and now your product, which isn't even for sale, can be charged for something that your business has no control over. Even if the ToS says Unity reserves the right to change their fees, I don't see how that can apply to products that aren't even being sold anymore.