Ok, that's what I always understood it to be. I didn't like the tone of the summary reports of the IPCC because that's the kind of phrase that was missing, IMO. In other words, there is no such thing as a "scientific certainty beyond doubt" that the sensitivity to CO2 doubling is within this or that interval, but rather, that "to the best of our current knowledge and understanding, the most reasonable estimate we can give of this sensitivity is within these bounds". And even "this can change, or not, depending on how our future understanding will confirm or modify our current knowledge".
It can sound as nitpicking, but there's a big difference between both. The point is that if ever after a while, one learns more, and the actual value turns out to lie outside of the specified interval, in the first case, "one discredited some scientific claims with certainty (and as such, science and its claims in general)". In the second case, that's just normal, because our knowledge of things improves, so what was reasonable to think some time ago evolved.