I don't know, but the idioms of the "white lie" and "polite fiction" certainly imply some connection between impoliteness and truth-telling, don't they?
I was reacting to @stemc43 who said "I'd rather work with...". Why wouldn't you rather work with kind and honest people? If you are picking your ideal scenario already anyway why not pick the positive version instead of the negative one?
On the other hand the idioms identified point to a long-standing understanding that sometimes, they are in conflict; a corollary of which is that one who always chooses complete honesty has likely failed to be polite from time to time, and one who is unfailingly polite has, like the curate describing his egg, likely given less than the total truth.
Most of us tend towards the politeness side of the tradeoff - we might, for example, describe a potential process failure when a more honest appraisal is that carelessness was the root cause.