If an essence emerged into existence, then this essence exists contingently. This is because the existence of any essence would be either:
The existence of an emergent essence can be neither necessary, nor impossible. Which means its existence must be contingent.
The existence of an emergent essence cannot be necessary. This is because necessary essences do not accept non-existence in of themselves. Whereas the existence of emergent essences was preceded by their non-existence. Given this essence’s prior non-existence, its existence therefore cannot be necessary.
The existence of an emergent essence cannot be impossible. This is because impossible essences do not accept existence in of themselves. Whereas emergent essences came into existence. Given this essence’s coming into existence, its existence therefore cannot be impossible.
Therefore, the existence of emergent essence is possible for them. And existent possible essences are contingent. Thus, emergent essences exist contingently.