Of course, we cannot know for sure what will happen in the hypothetical future. However, it does seem likely that Egypt would turn to some other country for aid if the US stops providing that aid. There are a number of countries that might be willing to aid Egypt.
Egypt sees itself as the strongest Arab power. It wants to have a strong military to help it maintain this image. For this reason, it is likely to seek aid in order to maintain its military strength if the United States stops providing that aid.
There are at least three countries that seem like logical possibilities if Egypt does lose US aid. First, there is Russia which does want to keep its international influence even though it is not as wealthy or powerful as it once was. Second, there is China, which is eager to have stronger ties with countries that are strategically important. Finally, there is Saudi Arabia. The Saudis have an interest in maintaining the strength of a Sunni Arab country that could act as a counterweight in the region to Iran, which is Shia and Persian.
Therefore, it seems likely that a withdrawal of US aid would result in Egypt getting aid from another country or countries just as Nasser did with the Aswan High Dam.