Interesting. I haven't seen this TSA set up before.

I like the idea of designating a line for security novices. That way they don't feel pressured by more expert fliers who, let's face it, sometimes are unreasonable in their expectations that everyone should have everything perfectly organized and know all the TSA rules by heart (I admit to emitting a few long sighs at times ...)

That said, I would have no problem assessing the line lengths and jumping into the novice lane if it was clearly shorter and moving faster than the blue lane.

You are absolutely correct about the black lane though. The sign clearly indicates it is not reserved for first class/elite passengers, so anyone should be free to use it. If that is not the case, they need to change the sign. And all airports I'm accustomed to allow elites to use the first class line, so the PSG telling you absolutely first class only is odd in itself.

I think this is a case of a new system being rolled out and not everyone being on the same page yet. My bet is (if it's a brand new system), it will all shake out in a couple weeks after the supervisors get some comments and have time to assess who understands it properly and who needs a follow up training.