It really depends. If you break the addiction and it could very well remain.

An example is tobacco/nicotine. If you stop smoking while you are on the drug and you break the addiction and the habit, you aren't going to reform that habit unless you start smoking again. And that's unlikely to occur because you no longer have the habit, you no longer have the chemical compulsion, and you aren't consuming any of it. Maybe stress could force a relapse due to weakness of mind but all things considered that's minor relative to the chemical addiction and the habit forming behavior.

An example where you may see relapse is alcohol or marijuana where the substance comes almost more from a social environment than it does from the chemical draw. Like once the habit is broken, it's still easy to be put into situations where recreational use is common and more or less expected on rare or semiregular occasions. That of course could lead to new habits forming and leading to relapse or it may not depending on what other (hopefully healthy) habits the user is now taking part in, their stress level, and other aspects of their life.

So the answer is of course that it depends but if the drug can reliably help people break habits then it can maybe also be useful in helping them avoid forming new bad habits or relapsing when the urge becomes too strong to resist.

What is the core of your point? That these drugs, that extend life, and reduce associated illnesses should be ignored or not used, because instead people can die sooner in some attempt to cure themselves the "correct" way?

A corpse cannot learn healthy lifestyle habits. A living person who lost weight the immoral way or whatever you're trying to say, can of course.

They said that this specific effect was largely sustained after stopping with the drug, so... ¯\_(ツ)_/¯