No, the weight gain is from the juice being high in sugar (like a fruit) without fiber (which a fruit has).
You’re basically drinking sugar and there’s nothing to slow down your metabolism or fill you up, so you take in too much sugar.
In theory if you mixed it with something fibrous like oats (that don’t have their own sweatener) maybe you end up in a better place (if you drink less juice and you eat/drink less caloric beverages/food throughout your day – i…e you trade bland oats and orange juice for a hamburger).
In general, adding things to your diet doesn’t help unless you’re also removing something (e.g., adding smoothies is great! … but not if you’re still having the hamburger and now also a smoothie vs water).