I'm finally in a position to replace my 15-year-old "HD Ready" TV with something a bit more modern, and it seems like the first choice I have to make is "what smart platform do you want?". Android TV looks pretty good, but my main concern is that a couple of years from now the OEM and Google will have dropped support and I'm going to need to buy a new TV again.
Am I worrying about nothing? Has Google or any of the OEMs actually committed to support periods?
I would suggest that you don't buy your TV based on the software that runs it. It's easy to get any of the numerous streaming box options and hook them up via HDMI. That way it's easy to upgrade quite cheap. Right now, the Shield TV is by far the best Android TV experience IMO.