Your travel conditions
are as well as having residence, not instead of it. When you go back, using the right of entry given by the new travel conditions, you will still/again have the right to remain in NZ forever. I don't know how they will show that, exactly, in your passport. If they put in a new sticker, it won't take the place of, or take away, your residence. Residence could only lapse if you, being outside NZ when the two years' travel conditions ran out, didn't renew your travel conditions in time to get back.