It definitely is one lesson Cadsuane has to teach, and a lesson that not only applied to Rand, but that all the Asha'man needed to be taught. The same global lesson, but of course it applies differently to each Asha'man.

The lesson Cadsuane tried to teach Rand eventually sank in, at great cost for her and for Rand as she approached this in a very dangerous way, and it brought Rand to become at last something even Cadsuane has not foreseen nor hoped for in her wildest dreams, a Champion of the Light she never thought to see. Cadsuane had little idea how formidable LTT was, and Rand is now that and more. Like Moiraine, she needs to face the fact she's done her part for Rand and she needs now to let him and move on to another task, and that task is foretold: she now needs to turn to Logain and the Asha'man, and finish there what she started with Rand.

As Brandon Sanderson pointed out, part of this viewing is already fulfilled, but there's more to come. The part that concerned Rand is most likely over. Cadsuane might have information for him, even bits of advice, but she no longer has any lesson to teach Rand/LTT doesn't already know. The part about the Asha'man however has barely begun (long ago, with those the women around Cadsuane invited to become their warders. It was the beginning of the lesson.) Cadsuane was "teaching" the Asha'man around Rand in parallel, but now Rand is distancing himself from actual leadership, she'll probably have to turn her efforts directly on Logain.

It sounds like it will fall on Cadsuane's shoulders, somehow, to make the Asha'man unlearn what Rand has taught them about what they are, how they should act and be, how they should lead. It sounds like before Cadsuane could approach this task, she needed to be "reforged" by Rand much the same way she had been reshaped by the Toothless wilder.