“We know that the Jewish people had to be in Egyptian slavery under the rule of the pharaoh for 430 years”
No, we were supposed to be there 400 years.
430 is only mentioned after they left Egypt, and those 430 years start from Bris Bein Habisarim; and have nothing to do with Egyptian slavery.
However, that doesn’t make Mashiach’s arrival any less likely- hopefully today!