Well the other posters answered, but in a nutshell because his record on consistency is non-existent.
Tax Reform, Immigration, Syria, TikTok, most of his original cabinet picks, he wanted to hang his vice president, Wikileaks and government leaks in general, the list goes on, his positions are about as fluid as any person I know.
Well he started the drive to ban TikTok, but did a 180 after a single meeting with a billionaire who owns part of it.
I have no idea what Trump's DOJ will do with this case; I doubt he knows or cares about the case himself. I won't be surprised either way they go with it.
What exactly is driving you to think that he'd abort a mission that he and his allies started?