Eventually body will go to "baseline" size meaning that muscle weight gained by AAS will be lost- tough must be noted that person had stretched his muscles/fascia so he it will be somewhat easier to regain size, plus he may be able to surpass his pre-AAS genetic limits ( a little bit) with good training regime and lifestyle even if he does not use AAS- again not by much
I've seen lot of really big guys stop training because various reasons- and overweight ones were back to being overweight, skinny were skinny again
Also, personal my experience confirms this
AAS have very powerfull effect on brain, and difference in brain chemicals last for 5X longer than cycle, and are very addictive
and IMO thats main reason why majority of guys are using gear- they dont want to stop and be what they were before, they dont want to lose "feel"