I think he only got jonin because Hinata's dad felt bad that Neji was fatherless because of him and pulled some strings to get him the title. We all know Sakura was high jonin/low kage tier at the start of part 2 but Tsunade had to keep her as a chunin because she feared that it would look like favoritism.I doubt she will be fighting them, Sakura likes Hinata, and Neji is somehow a Jonin, So he couldn't have fought Sakura, we all know how that would've went