The new "ambiguity" means, in a way adjudged favorable to literary, poetic, intellectually and psychologically well-devised and praiseworthily executed linguistic performance, uncertainty of meaning, or difficulty for the interpreter in identifying just what the meaning in question is: it means the old meanings of ambiguity with a difference. It means uncertainty of meaning (of a word or combination of words) purposefully incorporated in a literary composition for the attainment of the utmost possible variety of meaning-play compressible within the verbal limits of the composition.
"On Ambiguity". "Rational Meaning and Supplementary Essays". Book by Laura Riding and Schuyler B. Jackson, edited by William Harmon, 1997.