Rand's idea to kill the DO was before his epiphany. From what we know from RJ, such a thing should not be possible at all.

What we do know is that he means to Seal him away again, but better than he did before. That much we can glean from statements he made to people he wouldn't lie to. Similarly, his statement to Min shows that his plan is unformed.

Another reason why this is artificial is precisely because Egwene hasn't given logical reasons for opposing his plan. She's right that risking the DO lose before the very end is foolish. But she has more. Her Dream at least clearly indicates that Rand's plan is very dangerous. She should definitely have shared that with the Wise Ones and Elayne and Nyn, who all believe in her abilities. That she didn't only makes it more possible that this was a result of a shoddily introduced conflict.

As for stuff like the Cleansing... there were more than enough clues to Rand's plan well in advance. RJ never sprung something out of the blue there. It wasn't explicit, but neither was it without multiple clues in the series. This isn't a comparable situation.