There's no guarantee he would have made a difference. Lee was planning the reorganization of the Army of Northern Virginia from two corps to three for months prior to Chancellorsville and Ewell was always slated to get the new command. It is entirely possible that Ewell would still have been the commander coming in from the north on day one, and Jackson could easily have been the one coming in on day 2 instead of Longstreet.
Dr Robertson said once there would be no Gettysburg if Jackson had lived. Confederate troops averaged 10 mi a day travel. Army of Shenandoah.. 25 mi. Jackson would have engaged in Schenectady NY or Bangor Me. by that time, LOL
Either way Jackson would have been more aggressive once engaged. The ultimate result may have ended up the same but it certainly would have played out differently. Further, had Ewell still commanded the Corps in the north, then Jackson would have been commanding the 3rd Corps and he wouldn’t have completely disappeared on day two the way AP Hill did.