No it isn't.
Microfracture is performed in response to a permanent loss of cartilage. The body cannot regrow cartilage. The purpose of the procedure is to replace the (missing) cartilage with a "pseudocartilage" scar tissue that the body generates while healing from the microfractures.
The question then becomes the durability of the pseudocartilage and whether the player can adjust his activity level so as to reduce further stress to the area. Kidd is a low-impact player, so it's not too surprising that his pseudocartilage has held up. Stoudemire, even the less explosive version we see now, is a high-impact player, so his risk is greater. Zach Randolph, so far, is a success story, and he also stays pretty close to the ground. Kenyon Martin, another former high flier, is in the other category.
Stoudemire has the advantage that his loss of cartilage was smaller than for some other players, so the stress on the pseudocartilage won't be as great. It's possible that he has learned how to protect his knees well enough that he'll be able to complete his career normally. Even if that's true, however, he is not "completely healed" and never will be. It's like saying someone has perfect teeth because his cavities have been properly filled.
