Rabbi Henkin, in Bnei Banim and in Contemporary Tzniut gives a Limud Zechut for short sleeves and says that Dat Yehudit only really obligates women to keep their armpits covered. Does that mean that it would be completely acceptable in today's modern world to wear a short sleeved shirt (obviously one that is not too loose, so as to provide of a view of the body)? Thank you.