Obviously this year alone has been almost full of upsets and the famous one is when Canelo lost against Bivol when he is clear the heavy favorite to win over the defending champion of LHW. Haney surely doesn't want to be in the list of upsets that has happened this year or will about to happen, they should look further to avoid that from happening because Kambosos is surely preparing so much for this rematch because he really looks like an amateur boxer in their first encounter.
I do not think that Haney has to worry too much about it, if they were close in terms of technique then there could be some room for worry, but since Haney is so above of Kambosos and this is not something you can learn so quickly the difference between the two should remain wide enough for Haney to get an easy victory, with that being said it is important that Haney still prepares himself properly as we never know what it may happen during a fight.