I don't understand how a game without jumping can in any way be like Dishonored (AKA "Vertical Environment Exploration: The Game")
The most recent preview definitely seems to indicate attention to vertical exploration, though I agree that restricting jumping to preset locations is an especially odd and misguided choice in that context.
For me, what pushes the game from simply looking similar to Dishonored - which would only be natural, given how the latter drew inspiration from the original Thief series - to coming across as a full-fledged knockoff is primarily the setting and to a lesser extent the specific form that Garrett's powers take. As Borelli mentioned, playing a fighter/thief with magical powers matches up, but that could also describe most any recent action-RPG made with the goal of making stealth a viable alternative to combat, such as DE:HR or AP. (Even if the powers they give you aren't explicitly labeled as magic, they pretty much come down to the same thing.) And DLC and cinematic takedowns and such are a given in any AAA game.
But then you've got the setting: a crumbling city beset by plague and on the brink of chaos, where the leader is a ruthless man who rules with an iron fist and the protagonist tops the most wanted list. Sound familiar? There was also that character in
one of the earlier previews that people were comparing to Granny Rags. And then there's focus mode, essentially a combination of the Void Gaze and Bend Time powers, and swooping, which looks like it'll function as a non-vertical, short-ranged Blink. Taken altogether, it's hard not to get the impression that the game is, at the very least, attempting to ride Dishonored's coattails.
Edit: That earlier preview.
"War. War never changes." "Swooping. Swooping is bad." "Robes. Robes are always a bad sign."
...
"I'm not a kid anymore," she said in the angstiest voice possible. "Here, take my eyeliner," he replied. He knew what it was like for nobody to understand.
...
"GARRET I'M FLIPPING" "ME TOO ERIN, IT'S BEEN LIKE THIS EVER SINCE THEY TURNED ME INTO A FUCKING NINJA"
...