Gotten what is coming to one simply means that someone has received the consequences of their own actions. There are several synonyms that can be used to convey the same meaning, such as retribution, requital, comeuppance, payback, or just deserts. These terms are typically used to describe a situation where an individual has received justice, punishment, or reward that is deserved. Therefore, the phrase "gotten what is coming to one" implies that one's actions have resulted in a just outcome. It is important to remember that actions always have consequences, and it is up to us to determine whether they will be positive or negative.