You can set the start of integration for an audio Cut In at two levels:

At podcast level:

As of this day (midnight), all your podcast episodes will automatically be delivered with the Cut In stored here. Unless you have set corresponding restrictions by "Release date of the first episode" or "Release date of the last episode". Then of course only episodes that fit these restrictions will be considered. 

At episode level:

From this day on (midnight) your podcast episode will automatically be delivered with the Cut In stored here.

For episodes whose release has been scheduled in advance, you can also select "Release date" here to ensure integration from the release of the episode.