It wouldn't even have been hard to write your way out of this. Just have it so Minato kept his family safe from the many enemies he made during the war by keeping them an absolute secret to everyone but the 3rd Hokage who also thought it was a good idea to keep his wife who hosts the nine tails on the down low at the same time.I doubt that was entirely last minute. I'm sure he had neglected orphan nobody is actually the dead hero's son as an idea from the beginning, he just didn't plan out any of the details of how that would work.
Kushina was entirely last minute thing that probably only came up after his editor asked about Naruto's mom.
This could have been done well if Shikamaru, Chouji and Kiba treated Naruto like shit and Naruto only stuck around because they were the only ones willing to spend any time with him even if he was being treated like garbage. This is sadly not unheard of behavior for lonely children to desperately hang on to toxic groups in order to feel any sense of inclusion in any social setting.A lot of the side non-canonical stuff often features Shikamaru and Chouji as being some of the first friends Naruto had as a child. Even Kiba is spliced in there every now and again as the gang of boiz that would that cause trouble. Which when juxtaposed against it, makes the swing set scene and the "everyone hates Naruto" scenes absolutely fucking hilarious. It'd be less egregious if Kishimoto didn't rely so heavily on non canon material though to be "character development".
And boom, the 3rd hokage has an excuse for keeping this shit secret and sort of allowing Naruto's ostracization from the rest of the village to keep him safe. And why Naruto was both incredibly lonely and had a "group" to hang out with as a kid.
It took me 5 fucking minutes to come up with this shit, its not hard. Kishimoto is just a hack.