For sure, they will make adjustments with their techniques here. As they pretty know each other by now when it comes to the ring. They need to alter their strategies and we will see that if indeed this fight will soon happen. As both are relatively fresh with their previous fights, they can easily go back to their training routine. But in terms of odds, I am certain, bookies will favor Inoue here over Donaire.
That's expected, and we will see a major adjustment in that fight. Inoue will adjust not to get hurt by the counter of Donaire, while Donaire will try to end this fight early as that's his only chance to win, otherwise, he will lose his stamina to a younger champion. Inoue's jab is very effective, Donaire could not counter him easily because of that, Inoue should stick with that while continue to be aggressive.
Donaire's jab is also good in my opinion, the problem is that Inoue is so much faster than him, that's why he was beaten to it. And if he wanted to counter, he need to have a perfect timing, and usually that's what happen in the first fight. But as you have said, as the fight gets longer, Donaire's chances are getting thinner. He needs to get up and shoot for his left hook early so that Inoue will be on the defensive and can't get this jab easily.
I support our Filipino boxers but I just don't see Donaire winning against a young champion Inoue. We have seen enough in their fight before, and it was Inoue who completely dominates the fight, I think it's better if he will fight Casimero or Rigo, he would still get a belt if he wins.
We can check all the records of Donaire in https://boxrec.com/en/proboxer/48243
Loss to Naoya Inoue via UD
Loss to Carl Frampton via UD
Loss to Jessie Magdaleno via UD
Loss to Nicholas Walters via TKO
Loss to Guillermo Rigondeaux* via UD.
As we can see, most of the loses are via Unanimous decision, if it will go to the scorecard, most likely Donaire would loss again.