Congrats on your new van and welcome to the forum!
You can play video via USB from a flash drive. If you want to play video from an iPhone, you'll have to use HDMI.
I've seen several people report that they want to be able to play video from an iPhone via USB, but does the iPhone even support that? I know the iPhone supports AirPlay for streaming or mirroring over WiFi or HDMI, but I've never heard of anyone streaming video from an iPhone over USB to anything. I'm not saying it can't be done, just that I've never heard of anyone doing it.
2017 Pacifica Limited - Molten Silver/Mocha
8 Pax - Vac - SafetyTec - UConnect Theater & Sound
20" Wheels - Tow - KeySense - Splash Guards
2018 Mitsubishi Outlander PHEV GT