What makes you think Sakura is pregnant? There's no indication to that other than her hand being near her stomach. She doesn't even have a belly of a pregnant woman. Also Sasuke met Sarada before so this must be the point where he leaves the village for a long period of time, meaning that Naruto has been hokage prior to Boruto's birth or around the time of his birth.
Regardless I see no flaw..
No, Sasuke didn't meet her according to Sarada Sasuke left when she was still an infant and everyone is aware that Sasuke has been gone almost the entire time that she has been alive. If u are talking about the picture that was in Sarada's head that was her wish of how their reunion would go. U can tell by how it faded this chapter.
Also ppl usually stay in the same outfit. Sasuke is in a different one, the same outfit that all women of Konoha wear when they are pregnant, the hand over the stomach was done for a reason.
U don't see how in 700 Sarada already hated her father, but in Gaiden Sarada was so happy at the thought of meeting him that she activated Sharingan :|