the idea of Sasuke using Juugo as a senjutsu source was speculated back when it was revealed that only senjutsu can hold on to Obito's abilities.
And frankly it's better that it's a temporary upgrade because I don't see it matter to much against the fight with Naruto.
Despite the Curse Seal being an adulterated copy of the original source it still provides a noteworthy increase to a person's chakra amount, strength, agility, toughness, and jutsu potency. Sasuke would have no reason to forfeit that ability when he's intending to fight a senjutsu user in the near future. He's going to want to seize any advantage that he can find to even the playing field.
Kishi might re-implant the Curse Seal on Sasuke to compensate for the sage chakra that Naruto is using. In fact it's not that far-fetched to believe that he could learn to gather natural chakra independently without Orochimaru's juinjutsu. His entire upper chest cavity is made up of Juugo's flesh and chakra which he was given in the fight with Killer Bee. That might have granted him the same capacity to draw in natural energy as Juugo's clan.
Madara was able to use Hashirama's Mokuton much more plentifully and efficiently than anyone else who had his DNA. That's with his chest having been implanted with said DNA.
It's ironic because Sasuke, the Uchiha who has proven himself to be the mirror image of Madara, also has the genetic material of someone with a powerful KG embedded into his chest. That could serve as another parallel between the two clansmen.