Also, don't forget they will need to pull some PMCO planes out of service to resume DIRECTV installations, so I am sure that the fact that some planes will be out of service for a period of time has an impact on the E+ conversion rate.
DL promised that they would have AVOD in Y on some domestic birds like the MD90s, but they are flopping in that aspect. Even the first 744 that is currently undergoing mods with a new J cabin, but the Y AVOD installations have been delayed too. So, DL does have their own interior upgrade issues...