EU is open, West of Ukraine is open, even Russia is open (I know, I know).
If they can leave the region, this means they can go to any of the places above. If the situation is super bad and they're surrounded and nobody is allowed out of their city / town / village, then expedite won't help solve that. It's not like US would send a chopper to rescue visa applicants...
Hense, I'm a bit skeptical of expedite working. I hope I'm wrong. And for sure, I can understand why OP would want to reunite with parents sooner, it's a nerve racking situation. At the same time, if parents need to wait in Poland or other EU neighboring country, OP can safely visit them with US passport.