At present it is difficult to say with certainty that this is OnePlus TV although it sure looks like it. Google publishes a list of all the devices that are certified in different respects. For example, compatibility with the Google Play Store.
First spotted earlier today, a new OnePlus device now appears on the Play Store list. The device is simply listed as "Oneplus_Dosa_IN." While that alone does not confirm it is OnePlus TV, it does strongly indicate that it is.
India only… for now
OnePlus TV was recently certified by Bluetooth SIG. That certification applied to multiple countries, including the U.S., leading to the assumption OnePlus TV was set for launch in multiple countries.
However, OnePlus recently added more context stating OnePlus TV will launch next month but only in India. The company says the plan is to launch the new product line in North America, Europe and China but provided no firm details on when that might happen. Unlike with India.
With an India-specific reference in the Oneplus_Dosa_IN name, this would suggest the newly certified device is OnePlus TV.
Can't rule out other OnePlus products
While the indications do point to this being OnePlus TV, you can never rule out other products with OnePlus. It is possible this could be related to another device, smartphone or otherwise. Even the India reference can't be taken as solid proof as the company could be planning to launch another device there first.
It could also be the cast that other additional (regional) variations might be added to the list at a later time.
So, yes, while it seems likely this is OnePlus TV and that it's official Android TV, we'll have to wait for firmer confirmation to be sure.
Why official Android TV matters
Official Android TV does matter if you want to have the smoothest TV experience possible. The whole point of official Android TV is to ensure apps have been optimized for the TV platform. For example, Android mobile apps focus on swipes and that's something you can't do with a TV.
While it might seem a given that OnePlus releasing a TV, that's confirmed to be running on "Android," will run on official Android TV. Things are not quite that simple. OnePlus has made a big play for the uniqueness of its TV experience and that's something that doesn't usually lend itself well to Android TV. Android TV is very similar across the board.
At least, at the consumer level. Operators and other companies can and do adopt Android TV as the basis for their products. This allows them to heavily customize the experience and to a point where it is unrecognizable as Android TV. However, this is usually not something that's seen with TV-makers. Over-the-shelf products tend to arrive with a very consistent Android TV look and feel.