There is merit to the idea, though perhaps not to the solutions.
Whilst the mechanics might be the similar : sending in a potential review for moderation and possible inclusion in the employers thread / sending in a review potentially giving or removing a strike which can result in being restricted from this forum section. What would prevent reading this forum from a new account and then PM'ing or emailing the potential employer from your main account without then needing to enter this forum?
Any work relationship formed over the internet is intrinsically based upon trust. But whilst we have an employer reviews thread, there is less available for the other side, and even as a possible employee (on whose side this setup is slightly in favour) I do see it as slightly unfair and lacking.
Perhaps there should be some kind of 'reviews' thread, and artists could be encouraged to have their employer (paid or unpaid) send in a comment or complete a simple questionaire after a completed job. I would far rather see a thread that praised the good rather than one that only had a few negative comments on the bad. Not everyone that might apply for a job offer has a portfolio thread that could be commented on, but anyone who is interested in taking up work from this section of the site could have their name added to the list in such a thread. Possibly even with everyone starting out with a 3-star rating that improves with good feedback, and might drop with too much negative feedback. Whilst stars and occasional comments might not give a complete picture, it would at least give a vague indication to a new-coming potential employer who doesn't have much else other than postcount (and submitted samples) to go by - and may not be familiar enough themselves with pixel art to distinguish genuine quality.
References are one possible solution, but not always fully reliable. Also, sometimes not available from older work/clients, they can inconvenience people, and are not always available due to confidentiality / possible clashes of interest or many other reasons. Whereas a review from a previous advertiser here after completion of a job means there is little need to ever trouble the client repeatedly for references, and it bypasses the need for an old client and potential new one to have to deal with each other. So a sort of 'references'/employee rating thread could be a useful addition for employers and employees alike.
For the good artists with good history, this only helps to show their reliability and credibility.
For those with bad reviews (perhaps only shown as fewer stars) they will have to work harder and possibly offer reduce rates to try and rebuild those fences they broke along their path.
-Z-