You don't get the 400 CP until you Subscribe for the second month. That's why the Stipend comes 1 to 2 days after your Subscription date.
The Features Matrix does not state that you need to subscribe multiple months to receive the 400 CP. It states that if you are a Gold member, you receive 400 CP. Even if you are only a Gold member for one month, you are still a Gold member for that month - and - thus, should receive the 400 CP stipend that the site states you receive. There is no notation on the matrix which states that you do not receive it for the first month. Nothing in the FAQ states that you do not receive the 400 CP stipend the first month.
So once again, for that $15 - 400 CP stipend, 2400 CP worth of respecs on each Fed and 1600 CP worth for each KDF. 4400 CP. 5500 Zen...that's over a $50 value for $15 if you only run two characters (one Fed/one KDF). You get a universal slot, meaning you could rack up another 1600-2400 CP value out of that. It also does not take into account those features that remain when going from Gold to Silver.
So yes, that is something that I wish I had been aware of back when I first started.
If not for the Odyssey, Bortas, the time and money that I've spent on this account already; I would delete my toons and sub for a month. As is, I'll be looking at farming CP for 16 days with the four toons to get each a respec or dropping out $20 to do so. I've thought about deleting two of the toons, building them from the start with what I know now...and then face only needing to farm for 8 days for the two or spending $10.