What if the authoritative registry for such gTLDS give-up after seeing a low uptake? (Though I agree not all gTLDs are for commercial purposes.) I am not sure

What if the authoritative registry for such gTLDS give-up after seeing a low uptake? (Though I agree not all gTLDs are for commercial purposes.) I am not sure what ICANN has planned for such contingencies or if there are some rules already set.