Rather than a thug killing Thrawn like this on the eve of his success:
He just happens to become venerable and is very well respected…
Let’s just say, he changes the Chiss to something new and a force to be reckoned with to fight beings the galaxy has no clue about or what to do. And because of due diligence, the First Order comes knocking on his door, particularly SNOKE begging him for help against these enemies.