I noticed, a very long time ago, that guy's who worked for volume/pump did lose noticeable size/tone (tightness for a better term), ever as little as 2 or 3 weeks away from training. Guy's who juiced, a little more and faster...almost liking letting air out of a balloon.
Easy gainers tend to keep most of their muscle mass, but if only on the volume/pump protocol, do lose a bit of size, but still bigger than normal. Easy gainers, and about everyone else, kept most of their gains when training heavier and not so concerned with getting a pump. Preferring to train heavier may have many advantages when lifting and keeping what you worked so hard for. Including strength levels. Genetic disposition, after all, controls us all.
My ethnic/race background seems to produce easier muscle gains and strength. So there is somewhat of an advantage when training, being stronger/bigger than the normal population, before even starting to train with serious intent (or not so serous intent). . .Even the women seem stronger and athletic. Really the luck of the draw when being born, i guess. Good Luck.