I think it is meant that Harry set up Draco to be irreversibly autonomous with the Bayesian Conspiracy thing. And Lucius wants Malfoy to be the sincerely powerful scion of the Malfoy house, not just a puppet for himself, so he won’t mess him too badly.
Draco’s going to want to go back, of course.
His father may make him want what is best for him, what his father thinks is best for him, that is.
So maybe he won’t want to go back, after all.
I think it is meant that Harry set up Draco to be irreversibly autonomous with the Bayesian Conspiracy thing. And Lucius wants Malfoy to be the sincerely powerful scion of the Malfoy house, not just a puppet for himself, so he won’t mess him too badly.
I fear you mistake your hopes for reasonable conclusions.