Almost all of the streaming devices need to add some delay-latency to convert to digital and time align the system. Some streaming devices (Paradigm, Yamaha) give you the option of just using it as an amp for the line in so you do not incur this delay and this works great for TVs.

An exceptions for Sonos would be if you are using a device with analog outputs like some cable boxes you can connect the analog output of the device to Sonos and the delay with the TV doing its video processing MIGHT eliminate the lip sync issue if the delays are close between the devices. If you are using the analog output from the TV then the video has already been processed and the latency the Sonos adds is definitely noticeable.