Yes it can. The signal is being sent using the usual stereo carrier, which causes the TV's stereo indicator light to turn on, but the sound itself is mono. For example, can you find old mono recordings on CD? Of course you can. It's still 2 channels of sound, but the same signal on both channels.

For situations like this, you might want to try the 2-channel mode. The sound will still image in the centre, but it may sound a bit more fuller (if your main speakers are larger than your centre).

Best,
Sanjay