You're missing some steps here.
(1) This assumes he believes in the custom, which is something we don't know. It's inclusion doesn't mean he believes in it. It could be nothing more than a convenient plot device. He could also include in complete ignorance of the custom. We don't know.
(2) If he does follow it, would it be unusual for the midwife to keep it?
(1) Wait, didn't we establish that Kishimoto was old fashioned and several scenes throughout the manga were using old fashioned Japanese customs that in modern age are not as predominate? Now all of a sudden he doesn't go with old fashioned customs?
(2) I don't know, would it be unusual for a rabbi to keep a forskin after a circumcision?
(3) Gaiden makes it pretty clear that the bio mother is Sakura. Technically, we don't even know what Suigetsu compared the cord to. I assume Sarara's DNA as she is standing right there. Where would he get Sakura's to compare it too? There is no obvious source at the time. DNA in a vaccum isn't helpful if it's identity you are after. You must compare it to another sample. Therefore, Suigetsu's match would match the cord to Sarada, which would only tell you that Karin had Sarada's cord. Nothing more. It doesn't ID the mother, no matter who it is. The mother's identity is being assumed on the basis only she would have the cord. It's an unproven assumption (that is outright contradicted by the end of Gaiden). The comment about by Suigetsu about Karin being the mother was him making an assumption.
(4) The end of Gaiden answers openly contradicts that assumption. And what;s more, it;s occurs sometime later (i.e. when Sasuke and Sakura are not around). In other words, its written for the audience, not the characters. There is no point to this scene if Karin's lying as the manga would have already established the point this scene made (assuming she is lying). There is no motive or reason to lie to Suigetsu and it would makes sense she'd be pissed that he risked messing up hte relationship between her "friend" and her daughter.
Then what was the point of any of it at all? Why go through all the drama if it leads nowhere? That makes Gaiden completely and totally pointless. I know you're probably going to say "Obviously it is just to create a story and show the dynamic of SS," but that is not good enough. I don't believe any of it and it is actually easier to accept that Sakura is the adoptive parents rather than a biological one. And no, sorry, but Gaiden doesn't make it perfectly clear that especially when you have Naruto make a painfully obvious jest saying "Sakura doesn't have to be your biological mother to be your mother." If we go by what Naruto says, then Salad is NOT biologically related to Sakura. Kind of funny how we have to take Karin at her word, but apparently Sakura and Sasuke couldn't just say "Yes, you're our kid." No, they basically were unable to tell her such a simple and obvious fact.
No matter what reason Gaiden has there to exist, it is most certainly counter-intuitive.
(5) This argument isn't helpful anyway. Gaiden's entire point is that Bonds trump blood. Even if Sakura wasn't the bio mother, it didn't matter because of the bond she shared with her.
Gaiden sucks. I hate it, but I wish it wouldn't get torturer the way it does and extrapolate stuff from it that it does say or is outright contradicts by what's on the page. This really isn't the hill to die on.
Well, sorry Nate, but you're not convincing me....and Gaiden is not convincing me. Especially with the rest of the "canon" in toe for several MAJOR plot reasons.
-Sasuke hasn't been in the village for over 15 years. It has been confirmed in so many sources that are deemed canon. So how was Salad concieved? You mean to tell me Kishimoto doesn't know how sex works?
-Sakura and Karin are all of a sudden best friends? How did Sakura find Karin in the first place? This entire story plot is ridiculous. This always seems to be a cliche plot point that the Naruto teams loves doing. "All of a sudden Sakura is best friends with.....such and such girl and they go on adventures albeit breifly." Since when and why was Ino left out? Apparently the only person Sakura was not best friends with was the one the canon established were best friends in the beginning.
-There is no record at all of Salad's birth. Only word of mouth. Hell, taken at face value that means Gaiden proves that Sasuke and Sakura are NOT married and that Sakura is just "playing" as Sasuke's wife. They don't even have any pictures.
-Orochimaru has an entire lab made basically to genetic creations.....but apparently making a Sasuke baby is out of the question? Even Wolverine got a daughter this way through X-23.
-There is nothing to suggest that Salad is related to Sakura in any way. We can't go by what Kishimoto says because he is a liar. We can't go by what the story says because that lies too. We can't go by what any other person says because again...it is all lies and retcons. So what is it?
If Gaiden is proof of anything....it is proof that Boruto, the ending, and everything about Naruto is one colossal kitten up. Kishimoto has written on page that SS are miserable, Naruto has gotten dumber and has no idea what is going on, Hinata is useless and Naruto doesn't care about her to the point that if Sasuke needs anything it is his excuse to get away from his misrable family.
If we are to take Gaiden at face value, then that is what that all means....and I am guessing nobody wants to accept any of that either.
Edited by James S Cassidy, 05 April 2018 - 05:21 PM.