There’s too many variables for genetic potential and it will change every year as you get older and your body changes, thyroid levels fluctuate. It’s just too complicated and will vary from person to person. I know this much, the muscle you put on naturally is absurdly easy to hang onto, the muscle you put on with gear disappears fast, even if you continue to train hard, you may be able to hang onto the weight with caloric surpluses but it won’t look the same. Nutrient partitioning will shift and your midsection will hold more weight, traps and shoulders will shrink.
I’m sure with enough hard work you can keep some to a degree but genetic limitations are a bytch. There’s a reason people who use steroids attempting to advance with the intention of trying to maintain it naturally, end up just doing more steroids.