Adding an expiration date to a video will automatically set it to Unpublished, which will remove it from your catalog.
Contents that are scheduled to expire will be unpublished some time between 12:00 AM UTC and 12:10 AM UTC on the date that you set it to be unpublished. For example, if you set the video to expire on April 14, then it will expire on April 14 between 12:00 AM UTC and 12:10 AM UTC.
To select the date:
Navigate to the content you want to set an expiration date for in Content > Videos/Collection.
Click Edit.
Under the Visibility section, click +Add expiration date.
Open the date picker and select the expiration date.
Click Save.
NOTE: When you set an expiration date for an individual video, the video will be automatically unpublished and removed from your catalog, but it will NOT be removed from any collections it belongs to.
Videos inside collections remain accessible even after they expire or are unpublished. This is by design since collections can display videos regardless of the individual video's publication status.
To completely remove an expired video, you would need to manually remove it from each collection's playlist.