I've seen Higehiro, and the argument is still a stretch as the two main characters (in spite of the initial wishes of one of them) don't act as a couple with each other. If anything, the show is almost an Aesop in how not to be a pervert while dealing (sometimes intelligently and sometimes sophomorically) with the coinciding moral dilemmas that come with trying to a Good Guy(tm).
Domestic no Kanajo involves incest (well, step-incest) and better meets the argument of "author is a pervert" [1]. But yet there's no shortening of the title.
> This wisdom comes to me from a marketing director at Crunchyroll
Was an merely a opinion of his/hers as opposed to actual policy? And if it was actually a policy, do you think it might coincide with other elements (like how long the title of the source material is)?
[1] Although, for some reason, a woman writing a smutty telenovela script as a light novel doesn't generally register "perversion" to most people. I wonder why.