Can I use the USB port with a USB to MicroSD cable to charge my Oculus Go? The Go only has 2 hours of battery life so this would be quite nice if possible.
Of course you can’t.
If you want a portable charger for your Oculus Go (and your Passport Wireless Pro)
Buy a Power Bank … that’s what they are made and designed for.
My laptop can charge my phone so I wouldn’t have been quick to assume the WD hard drive couldn’t do something similar
The internal battery of the MPWP can be used in power bank mode via the USB Type-A connector.
While running some very short adhoc tests using an adjustable electronic load and a quality USB power monitor, my 4TB MPWP was able to deliver a touch over ~1.50A @5v before disabling power to the USB port. (@~70% battery charge level, MPWP powered down.)
Published specs of an Oculus Go’s power supply, is 5v @ 2A… So you’d probably be ok if only charging the Oculus’s onboard battery or using the Oculus with a nearly full onboard battery, but your mileage may vary.
Regardless, the battery in the MPWP is only ~6400mah and I seem to recall the power bank feature may actually be disabled at lower battery levels (< ~20%? capacity). Given the limited battery capacity, cost of replacement for a worn out battery (entire MPWP for most folks not willing to track down 3rd party parts for a battery pack swap, unit disassembly, soldering skills, etc.), and the low cost of the alternatives, you would be better off with a stand alone power bank as mentioned above.
If you are looking for something extremely portable, I have a couple of these I travel with for emergency power for smart phones, cameras, etc: Anker E1 I’ve found I’d rather carry multiple E1’s than my larger power banks.