"Do the wives like piano?" is correct; "Do women like the piano?" is correct; "Do the women like the piano?" is not correct. Does the choice to translate "les" literally affect whether or not "femmes" means "women" or "wives"?
No, it doesn't. "Do the women like the piano?" is a perfectly good translation. I think Duolingo has now changed it so it is shown as correct.
I typed les femmes aiment-elles le piano?, which was rejected. I want to know if this is a genuine error which should be reported, or if this type of construction is too colloquial/informal and not standard French.
Sounds very close but Duolingo is expecting a more litteral translation.
"Est-ce que" forms a basic question in French, the equivalent of which is "Do" in English. While your suggestion is a great literal translation, it's a very rare way for someone to ask that question in English; rare enough that it doesn't deserve to be a correct answer on Duolingo.