Graduate School Application: should I mention where my working paper would be submitted Follow-up on
Does unpublished paper matter for U.S. graduate school application?

One of my papers is ready and my research adviser wants me to submit it to one of the best journals in my area. But it's actually proposing a new idea so there's still a lot to be done (in the paper I pointed out many tests that should be carried out), so I'm not entirely confident about it getting past the review.

On one hand, I could submit anything to any journal so it's not necessarily saying mcuh about the quality of the research, and it would look pretty bad if it failed the review; but on the other hand, my adviser is kind of a semi-big deal in the small circle (I mean, he knows some people and some people know him). So those who know him will understand that the paper would be examined rigorously by himself before submission.

So, should I add anything to my resume about this? I understand the answer will probably be largely opinion-based, so I'm sorry if it's violating any rules here!
I'm in a business school and our norm is to list a submitted paper as "under review at so and so journal" on our CVs. People tend to update their CVs in this manner before heading off to the job market so that selection committees can see that they have projects that have progressed. I've served on a doctoral admissions committee in our department. Knowing that an applicant had a paper that was far enough along to be submitted would have put that applicant at the top of my consideration list.