So where's the image from, incidentally? Your post didn't make it entirely clear, sorry, though I'm guessing it's Diablo, since you referenced that? At any rate, what I'm seeing here is armour; there's no two ways about it, these characters are wearing armour. Barb does not start with armour and they shouldn't, so while the designs look neat in their own way, they aren't really appropriate for D&D barb starter gear.
That aside...
Personally I think a Female Barbarian having her breast out makes sense and would be fine ( women fighting topless was an actual thing, there's even a Viking Saga of a woman doing it against Native Americans ).
I think of the Picts, the early proto-scots that terrorised the Roman army, a bunch of painted up screaming people that had a tendency to run into battle nude, or with nothing but their underwear and a shawl, to keep warm, you know? And yes, the ladies were also often nude.
Indeed, I second that and would like it too, but, I do want strongly to say that I'd like it to be a
choice. I'd like to either be able to pick from small short list of starter outfit appearances, that may include variable amounts of exposed skin - everything from full fur and pelt light clothing, to other culturally-reminiscent simple clothing, and yes, up to and including bare-legged and bare-chested, maybe with some battle paint, for both males and females.
Breasts are not obscene... but at the same time I don't think having them out should be default, unless it's a default we can personally choose or not.
I've got characters that wouldn't bother with a chest band at all (mostly due to lack of personal need for such), and characters that would absolutely cover and support their chest (again, more due to practicality and support/restraint than showing off); I'd like to be able to choose.
I agree that the current in game Barb starter gear feels bland and uninspired, especially for females.
