Sterling was in a very tough fight, adrenaline dumped, smashed to the side of the head with a flush knee, confused, etc. As a fan of his I didn't want him to go back out there. The knee seemed to shatter his will to continue. Yan certainly earned his "No Mercy" moniker in that performance at least. I personally don't think Aljo should have even been given the option to continue considering how blatant the foul was. Yan should have probably just been disqualified on the spot. Just my opinion of course. Others would find that much too harsh.
It think while it's possible Sterling may be more intimidated by Yan in a rematch, it may actually work to his advantage. Aljo has a very analytic mind for the game and I have no doubt he will pour over the data from the fight over and over before the rematch. I don't know how much adjusting Yan will do for a rematch considering he probably doesn't feel the need to change much and he's probably right. I think it'll be all on Sterling to effect the outcome of the rematch.