Not necessarily. All this could be reported up to airline HQ through the satellite link and then the IFE/customer WiFi could be downloading it again to serve lo

Not necessarily. All this could be reported up to airline HQ through the satellite link and then the IFE/customer WiFi could be downloading it again to serve locally. That would prevent any need for direct connection between the systems. Is that how it works? I doubt it. But it could be done.