Gjally and icebreaker were unique weapons and should come back. The problems weren't those weapons but bungie's awful design in boss fights. Every boss in year one was just a bullet sponge and had no unique mechanics. Name one boss in the raid that gjally would absolutely destroy. You can't use it on golgoroth because rockets are useless on his crit spot,black spindle would out dps it on warpriest, and ToM outperforms everything on daughters/Oryx. This is how their other bosses should have been designed and gjally would not have been an issue.

I personally think if prenerf y2 Ghorn was introduced it would only be put away for golgoroth and oryx. Back in Y1 Ghorn slaughtered BH for DPS