Oh ok, I figured since TB was based off it there was commonality!
Torchbearer uses, as its version of "say 'yes'", "Good Idea" - which is mostly
GM control over pacing/focus. Because of its turn/grind structure, Torchbearer establishes stakes for tests that are independent of player-authored PC priorities. When something is a good idea, no test is required, and no turn is marked. So the GM gets to decide what moments of play will carry heft - ie mark a turn, but also give a test which is central to advancement. Torchbearer also assumes a significant degree of GM prep, which affects these decisions about pacing/focus.
Torchbearer is more GM-driven than Burning Wheel.
I'm assuming packed into "say yes or roll the dice" is an inclusion of also "but if the fictional position would make it impossible say no?"
I don't think Torchbearer discusses this in the context of action declaration, or at least no in terms of saying "no". It's discussed in terms of the players needing to describe what their PCs are doing.
In Burning Wheel, it's discussed separately from "say 'yes'" - and is presented as a simple credibility test, via a couple of examples: at one point, the GM says to the player "It's a dragon - I don't think there are going to be any Routine tests"; and at another point the rulebook tells the reader that there is no roll to find beam weaponry in the Duke's toilet.
The Adventure Burner discusses saying "no" in the context of Wises, where a player's intent might clash with GM secret backstory. It's a bit awkward, because there's no clear rule or procedure here. It's a weak point in the rules.