Does the husband sin if he allows his wife to communicate with a friend of hers from before marriage, knowing that the meetings will be in public places?

The relationship between men and women who are not mahram (definition), under the guise of friendship and brotherhood, is a door to fitna (temptation, discord) and a means to corruption. It is not permissible for a husband to allow his wife to communicate with a non-mahram man under the pretext of friendship and brotherhood, whether their meeting takes place in public or private places, and whether the communication is via phone or otherwise. All of this contradicts commendable ghira (protective jealousy) and qawamah (the husband's responsibility as protector and maintainer).