It seems as though a last minute issue known as "the entirety of Battlefield 4" (ha, jokes) showed up for Battlefield 4 Naval Strike on the PC. As a result, DICE is delaying the release of the new expansion just for PC owners. Console owners running with Premium will get their hands on Naval Strike on schedule (today).
However, we are delaying the launch of Battlefield 4 Naval Strike on PC. We’ve detected an issue and it needs to be solved. Quality is our number one priority and we will not release Battlefield 4 Naval Strike on PC until we feel it meets the highest quality level possible. Once we have a confirmed date for PC, we’ll be sure to update those players on our official channels. We appreciate your patience and look forward to seeing everyone on the Battlefield.

Hold the phone. You mean to tell me that DICE found a critical bug before they released new content to the public? Get the hell outta here!