It's possibly a bug -- it's not a display thing, at any rate.
The main problem is that if it can't find enough ships to fill the order of the CPA, then it just fills what it can. If it tells you that there will be a wave of 5k mark II ships, and there are only 2.5k mark II ships, then that's all it will send. It should also send the 500 mark I ships that exist (for example, if that's the case), but I'm not sure that part is working.
As far as what to do when there are simply no more ships available for the AI to send: well, I'm open to suggestions. It could send higher-level ships, or warp in new ships, or just do what it's doing.
Oh: and, it should try to break open barracks, which it doesn't currently do.