He's definitely 1:4 scale... now based on your preference for his actual height / size, it depends if you think Thanos is supposed to be 6' tall, or closer to 7'-7'6"ish… If you think he's supposed to be closer to 6', this might get mistaken with a 1:3 scale label. If you think Thanos is closer to 7'6'"ish… BIG… then he's definitely 1:4 scale.
The teaser images in this thread give you a good idea of how involved the design is. It isnt classic "simple" by any means, but it was inspired by the classic look. As you can see in the teaser, he doesnt have a single gold strip going down his chest, but segmented armor plating… its similar thinking across the piece. Things are broken up, re-worked, etc.
To me, if you know the movie version, there is no mistaking this guy for the movie take, especially with the portrait. Fans who want a more "classic" take on the portrait style, they'll be happy… Fans who want the costume design follow the classic look to a "T", they wont be happy…
Im stoked for the full reveal. The 12 Days teaser was a color 3D render, the guy's in physical paint now, and he's looking phenomenal… You guys will see him wayyyy before SDCC. Not sure when exactly, but it's not too far off.