Has anyone figured out why xin was buffed in the first place?

Riot threw some darts and it hit Xin Zhao,

My favorite champion to pick into Xin jungle is , you can be miles behind and still win 1v1's thanks to your E.

sated

The fastest it get sated is around 13-18min usually, so presure the map before that happens. Or if u want to fight him after he get sated 1v1, your best option probably is other sated jger that is also tanky Shyvana comes to mind like the other poster have pointed out. Granted you dont really need to "fight him" fight him. You can just teamfight and peel for your carries. For this you can pick Gragas. There is alot of options, but of course if he got fed you probably just gonna roll over and lose. But hey if he got fed somehow, he probably deserve that win.

He mainly got buffed because his pick rate was too low for Riot's standards. He already had a near 50% win rate with majority of the player base maxing the incorrect ability first before the buffs.