It has been shown many times that TV's digital output can be a roll of the dice. Sometimes the output will only do 2ch PCM, other times it will only output 5.1 if the source is a non DD+ or 7.1 format. Other times it might decode everything fine to whatever you need (rare).
This varies from model to model as well as manufacture.

It is something that can possibly work but a professional should never rely on.

I still struggle with why people (including some dealers) can't get it thru their head to just get a $49 or $99 streaming box and velcro it to the back of the TV (or where ever it needs to go).