Minato from twenty years ago reported everything he knew to Kitahara Kaede.
That was only natural.
At this point, the Hidden Leaf Village was under the Third Hokage's control. He might not have had much ability, but he still cared about matters of status.
So, based on their respective positions, Minato naturally reported the situation to Kitahara Kaede.
Besides...
A future Hokage had come in person... perhaps that meant this mission was very important.
That made it even more impossible for him to keep anything to himself.
And Minato's actions from twenty years ago earned the approval of the big shots in the little group.
Virgin Minato, You Have a Son! (Please Enable Auto-Subscribe, Please Subscribe in Full)
Observing Kitahara Kaede? (^_-)
Hashirama Senju: Minato, you did pretty well here.
Hashirama Senju: Once you made the right judgment, you reported the information.
Minato Namikaze: Um... since I don't have memories of this, hearing you praise me like that feels kind of strange~.
Tobirama Senju: Then why don't you have memories of it?
Minato Namikaze: Maybe the me from twenty years ago was worried that something might go wrong with events in the future, so he erased everyone's memories.
Minato Namikaze: I know that ninjutsu.
Minato Namikaze: It's a memory-erasing ninjutsu, and it also came from the Uzumaki Clan. If this was twenty years ago, then I should already have been dating my wife.
Hashirama Senju: I see. Congratulations.
Hashirama Senju: Just like you, I like Uzumaki women.
Mito Uzumaki: Don't say that kind of thing here.
Hashirama Senju: Um...
Hashirama Senju: Mito, are you unhappy?
Mito Uzumaki: No. I just wanted to remind you what is more important. For example, don't you see that Naruto and Yamato aren't here right now?
Hashirama Senju: That's true.
Indeed, neither Yamato nor Naruto