The original plan was for Paddon to do only 9 events this year. Abbring would jump in the 3rd car for the remaining 4 events. However, Paddon then came up with more budget so they entered a 4th car in order to let Abbring drive his rallies.
I think we won't see a 4th car being entered next year again, especially if Paddon moves up to the main team and doesn't need to pay anymore.