釆 (not 采) depicts an animal's paw print - an ancient symbol of discerning by tracks. As radical it places 释 in the family of distinguishing and explaining, fitting the meaning to clarify or release.
The right side is a 5-stroke graphic reduction of 睪 (supplying the sound shì in traditional 釋). Modern simplified collapsed 睪 into a shape visually identical to 圣 - they are not historically related; this is a graphic contraction only.
