I just set up a new iPod touch and installed FM Go 16. (I'm not sure the exact version number currently installed; it's prompting me to install 11.0.3)
I connected via the wifi network to a database that has a script with an Insert From Device script step to scan a barcode and save it into a Global field in the current table.
The Insert From Device script step does not happen. The camera doesn't appear, nothing.
HOWEVER, when I saved a copy of the database onto the device and tried to scan on the now-local copy, I got the dialog "FileMaker Go Would Like to Access the Camera" system prompt with the options "Don't Allow" and "OK".
I would conclude from this that instead of seeking permission, FM Go when running the remotely hosted file is only checking to see if there is permission, and when it doesn't see existing permissions it skips the Insert from Device step.
Possibly related topics: FM Go 16: Insert from Device (QR code) with global field