I am currently playing by delaying the campaign mission until I've developed the whole sector, which is how I noticed the lack of Battleplans.
I am 62 turns in, never used a Battleplan but still have only 3 of them, even though the tooltip for the Listening Post states I should get one every 4 turns. All the plans I own currently are from raiding a ship mid-combat and I haven't used any yet.
This is especially annoying since I can't take Obsidian Depths like this.
If I remember correctly we weren't able to upgrade the listening post in the beta. Could this be an oversight?