OP said they have both an Nvidia Shield and a Blu-Ray player so there is no single set-top box. Running from the TV means you catch all audio output no matter the source.
Yeah, the only device with a "passthrough" is the TV itself, via ARC. If I had a 4k capable receiver instead of the sound bar, then it could act as the hub and output everything to the TV.
Previously I did have a receiver, and no Nvidia Shield device. The TV has Android TV built in to it, so I still relied on ARC most of the time. The TV's built in functionality got too buggy (borked video, audio dropouts during loud scenes) and slow to use day to day, so I added the Shield. My receiver didn't support 4k, though, so I plugged straight into the TV and used ARC still. I since replaced the receiver and all the mid-size speakers with a 5.1 wireless soundbar to free up shelf space in that room. Since I know you're curious, the receiver got paired with a 1080p plasma TV in a guest house where it can retire with dignity, and the speakers got moved to a bedroom, connected to a pre-HDMI receiver and a cheap Bluetooth dongle.
