Definitely. There is a significant risk in failing to communicate accurately by deciding that honesty is all we are obligated to do. This seems inconsistent with the ideal that rationalists should win, in this case winning over the difficulties of accurate communication, rather than simply trying virtuously.

More broadly, though, there is an ambiguity about what exactly honesty really means. After all as Douglas Adams points out, speaking the truth is not literally what people mean when they tell each other to be honest - for one thing this is neither a sane or a terminating request. I suspect this is one of those cases where the graceful failure of the concept is socially very useful, and so the ideal is useful, but over achievement is not necessarilly any better than under achievement (at least not in societal terms).