[[ If Itachi was alive, I don’t think it’d ever happen. (Sasuke and Sakura getting together, that is.) 

Part of why Sasuke was able to be harassed into eventually giving up and accepting a relationship is because he’s isolated from people who would help back him up or demand he be given his space. Taka isn’t traveling with him, Itachi is gone, etc. And if we’re going to believe that Karin is aiding Sakura (as the whole timeline during the pregnancy is unclear), Karin is actively working against Sasuke being able to say no. In Sasuke’s novel, Karin makes comments about Sakura not having anything of Sasuke to remember him by in his absence, and knows she has feelings for him (which is why she gets her the copy of the team photo). 

If you introduced Itachi into the situation, that by itself would just help Sasuke’s self esteem by loads. He would prioritize Itachi and traveling with him,and would definitely not be as susceptible to Sakura’s stalking/harassment simply because he’s got his brother to think about. 

If Itachi could see it was at a level that it was actively interfering with Sasuke’s life and it was crystal clear Sasuke did not want the attention, he would try to coax her to go home, gently.

Itach’s the kind of person who would think it was admirable that Sakura and Naruto never gave up on Sasuke, no matter what he did. He does think this for a very long time. But since this situation is post Edo-Tensei and post-war, Itachi would eventually realize that Sasuke can choose who he is and isn’t friends with, and that just because Sakura loves him, she isn’t owed any of his time or attention (just like Itachi realized just because he did what he did to protect Sasuke, it doesn’t mean he’s owed an ounce of Sasuke’s forgiveness or time.) That’s a very important lesson for Itachi to learn, not just for how he interacts with Sasuke, but for how he sees others interacting with Sasuke.

He would never  be mean or cruel about it. But once Sasuke’s firm on not wanting Sakura’s attention, Itachi would act as his backup so Sasuke can’t be cornered into it. He still thinks it’s nice Sakura has feelings for him, but the nicest thing Sakura can do for Sasuke is actually wait. Maybe one day he’ll return her feelings, Itachi wouldn’t mind, as long as it was purely Sasuke’s decision without any pressure put on him. Maybe he won’t! That’s not Itachi’s decision to make. It’s up to Sasuke. 

But– if you mean being reanimated long after they were together and had Sarada, it’d be too late.

By this time there’s nothing he can really observe that would make him act. It’s already happened, and unless something drastic happens, he really has no reason to assume that Sakura chased Sasuke into submission. He would just be under the impression that they fell in love and married and had a child, even if it is unfortunate that Sasuke’s work keeps him away from his family for years at a time. Without Sakura’s behavior during that blank period to go off of, he just thinks that Sakura’s love for him paid off and that what they have is good. This is just something that can’t be helped without drastic intervention. ]]