Does equipment fall off when a unit dies but gets saved by Guardian Angel?

No, equipment does not fall off when a unit is saved by Guardian Angel.

According to RiftJudge FAQ #8298, FAQ #674, and FAQ #5370, when a unit is saved by Guardian Angel, the death event is replaced and prevented. Because the unit never technically "dies" or leaves the battlefield to go to the trash, the equipment remains attached to the unit.

As noted in RiftJudge FAQ #8433, the unit retains its state—including all equipment, buffs, and damage—when it is recalled to the base.