I've been reading about close vote review audits for quite some time now. I used to think that these audits appear only for users who do not have either of Steward or the Reviewer badges; which is why, I never had faced any reviews until a few days ago.
I think it is either a bug or an easter-egg; that the close vote audits can be skipped/removed completely from appearing.
I've tested around with it for quite some days now, and the trick is to just use any kind of filter; either by tags or by close reasons; in the review task list.
I haven't been able to test it with other review queues as those do not get as huge as 50k.
I reset my filters again today (after nearly 2 weeks) and was provided an audit within a few minutes: https://stackoverflow.com/review/close/2241112 (of course I passed :/ )