I sort of doubt that hard wired vs ethernet makes a difference as far as requirements for Sense to see a TV. Broadcast data is broadcast data. Meaning, I don’t think that Sense will only detect TV’s on Wifi or vis a versa. But it will be effected by the properties of your home network. So in your case changing to Wifi may make a difference.
Once you start bridging networks (LAN to Wifi as in an AP) that broadcast data can start being treated differently. So in @chris1’s case, maybe the AP is doing some filtering, so the data wasn’t making it across the AP while the TV was hardwired, but once the TV was on the same AP as the Sense, they were able to see each other.
In @russ’s case, it could be that the Mac address change threw everything off. Looking at a post from a while back, it does seem that it might be a combination of network data AND power that lets the sense feel good about ID’ing a TV.
Then as mentioned in the post above, the TV has to be doing the right things while “off” for this all to work. So different models and manufactures and software versions are all going to come into play.
All of this is to say that moving a TV to wifi may make it detectable in a specific persons environment, but I don’t think that WiFi vs Ethernet is a limitation on the Sense side, it just may be a limitation on each persons specific home network with their specific TV types.
I have two different Smart Sony TV’s. One on ethernet. One on Wifi. Both allow WOL and remote control via Alexa, so I know they are listening all the time, but neither has ever been picked up by Sense.
I did add some HS110’s to the TV’s and tied them to my Nest “Home” or “Away” status as I found that the TV’s were drawing around 15w constantly, and once an hour would go to about 80w for a minute or two while they did some checks. So now I power them off completely when Nets sets the home to Away.