One thing Swedish developer DICE have NOT been known for recently, is their stellar quality assurance. What with the borderline broken state Battlefield 4 was released in and all that. Yet, it seems that's the reason why the game's latest DLC, titled Naval Strike, has been delayed. According to the Battlefield 4 blog, DICE have detected an issue, and this issue must be fixed. Therefore, the DLC that was scheduled to release today for PC and console Premium members, will only show up on the consoles.
"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."
What the issue is, or indeed when it'll be fixed and the DLC will finally be released, isn't specified in the brief blog post that seems to act more as an extra excuse to promote the DLC rather than explain the actual delay. One thing DICE absolutely are known for, is being vague about things like this. Because the consumer apparently doesn't really need or want to know. It's just money, right?