If something is preordained, there is often the sense of fate or some higher power setting things in motion / making things happen. For example, if someone has a great sports career with a lot of luck, and they always seem to be in the right place at the right time -- we might say their success was preordained. A similar expression is: It was meant to be. There is a sense of divine intervention or intercession. It might be said, for example, that a young couple's love is preordained -- when they grew up together, were always friends, their families were friends, etc... It was meant to be that they would get married... It was preordained...

Preordained means to plan or decree something in advance. If it is preordained that somebody will be chosen for an important position, it means that the decision has already been made ahead of the actual official announcement.