The well established and by then fairly ancient conventionalized means of symbolizing "radiance" or "glory" in painting and sculpture was the halo, annalex. Not horns.
Michelangelo took the erroneous translation of Jerome in Exodus literally. Apparently the church hierarchy and laity did as well. And so, a statue of Moses with horns was installed in The Church Of St. Peter In Chains in Rome, in 1515, and it remains there today.
Oddly, Jerome's translation seems to have been bypassed in Bibles typically used by Catholics since the 20th century, despite the Latin Vulgate having been declared free of error.
Not well suited to sculpture. I do not argue in favor of Michelangelo's statue, simply pointing out that the "horned" metaphor was well understood in his time, as was St. Jerome's intention. Also, art was understood correctly as a medium of theological reflection and not naturalistic portraiture.