I'm definitely a bit concerned about the issues involving their takeoff angle, especially combined with my own similar issue in their direction. But with that said I think most well-built stations on the east coast will have a better than average shot on many bands, especially 20 and up. Lowbands will be problematic for many reasons, not the least of which is the short period of mutual darkness to a part of the world with a crap ton of active DXers with big stations.
But what I think might be the saving grace, despite the mountain to their northwest, is the relatively short distance to Zone 5, meaning expected takeoff angles will be closer to 10° than 5, and the fact the path is non-polar, so no auroral oval attenuation. It's certainly not perfect, and JA and VK will do much better than North America Zones 4 and 5, but I think most of us will be able to put at least 4 and maybe 5 new bands in the log, assuming they can get everything going and stay at least 10-12 days.