Well, it's probably not equivalent, but it's a good hint (aka : you can't express clearly something that isn't well structured in your mind).
Plus, it also let me test verbal skills themselves, which is extremely important as soon as you're working in a team.
Another way of looking at it is that "finding the right word" often means find the good "fit" between abstract concepts shapes or feelings, and a construct of known language items. That's precisely what you're doing as a developer.
Ok, so it's based on reasoning full of assumptions that may be wrong, not on empirical evidence. For me, it's quite hard to think aloud when solving some problem, because it forces me to translate what goes in my mind into words, which is quite distracting, I cannot fully immerse into the problem.
I suppose you're more a "tool" developper than a "business process automation" one.
In the latter, you very often have to talk through the problem with your customer.
But it is an assumption indeed... Only it is based on my personnal experience.
As for the comment mentionning google developpers, the ones i see are good enough verbally to talk about their jobs at google i/o.
Another way of looking at it is that "finding the right word" often means find the good "fit" between abstract concepts shapes or feelings, and a construct of known language items. That's precisely what you're doing as a developer.