User blog comment:Xilinoc/Ch. 600 - SNIPE/@comment-6657474-20141010041227/@comment-5693502-20141010081719

That actually sounds quite sensible. I wouldn't put it past them either, they should know Yhwach better than any other Shinigami still alive.

Although the only reason Ichigo will be the one to defeat Yhwach is because he's the main character. I can see no other reason in-universe why he would have any other chance of winning outright.