We are looking to delete records in our Marketo database to clean it up. We currently have our Marketo synced to Salesforce.
Do you currently have a "one to one" sync between Marketo and Salesforce? If yes:
1. Yes the records will re-sync from Salesforce during the next sync cycle.
2. If you need them not to sync you need what is called a "sync filter" essentially it is a field in salesforce that says "yes send this record to Marketo (or no don't send this record to Marketo). there are MANY posts on this. Here is a good one.
If you already have a sync filter in place.
1. Before you delete from Marketo be sure to update whatever your sync filter field is to ensure they don't sync back!
As I said above, there is a lot in the community on sync filters, they are a popular topic, but they don't come without some things to be aware of!