Yeah ...true but I thought chapter 631 was just for fun sake
And it's completely true that Hinata isn't like Kushina .....
The only thing that was made for fun sake is Sakura's headbut to Naruto. But even that served the purpose to remember Minato of his wife. This isn't a fandoujinshi where there is nothing wrong if you do things that are out of place. This is his lifesaving and serveral people are working together with Kishimoto on it. If he intented to let this only be a fun moment, I'm sure somebody would have advise him to simply let it be done after the headbut. It wasn't made for fun, but to conclude one of Kushina's wishes.
This would have been concidered something that is done simply for funs sake: