I'm planning a deployment of a new Apex class and 2 triggers (fully tested in sandbox with SeeAllData=false) that processes new fields, some others will change (formula fields, etc). We already have approval processes and validation rules in place for the objects the deployed changes will affect, my question is: what happens to the existing records of the affected objects when the changes are deployed? Are the approval processes and/or validation rules triggered and run again for all the existing records?
We will have new data flows from an object's field to an other object's (new) field and I'm not sure if, after the deployment, basically everything will fail (the existing processes) because there will be missing data in the newly created mandatory fields for the objects.
If the problem is not clear I can try to give a practical example of the data flow.