Honestly, it feels suspicious.
It’d probably be better to invest the (substantial) work done in reviewing the submission in a more structured interview process where the traits can be better assessed.
If you make the candidacy process a significant burden to the candidate, I’m weary you might make it a similarly significant part of the selection criteria, just because otherwise good candidates who are less eager to work for the company might not have the time to apply to it. That the process rejects a large number of promising candidates is already predicted in the article.
Can you observe any signal on the candidate background that’d indicate they could be consistently eager to leave their present companies?
Yes you do, implicitly.
This is why I asked if you can detect any interesting signals in your candidate’s profiles that diverge from the overall candidate pool (hard to get stats on the people who don’t apply, but I think you understand where I’m going).
For the record, I’d LOVE to see that kind of data.
(All companies should make their hiring process transparent and public).