1. very unlikely the EB2 will be retrogressed, only moving foward make sense.
2. if your PD is current now, and your visa become unavailable AFTER filing the case, you can negotiate with AUSA to hold your case, we have a few cases like that, and were approved soon after PD current
3. WOM will only focus on the PROCESS, NOT the final result. In other word, winning WOM only make USCIS to process your case, not necessary APPROVE your case. That's why only recommend WOM for those application 99.9% should be approved(like I-485, not I-140). On the other hand, if very unfortunatelly you lose your WOM, it only mean your case will be continuing pending, not affect the final result.