Despite being transported to what seemed to be the future, Minato wasn't angry. He was, however, feeling a bit frustrated, possibly annoyed with Obito's insistent impulsiveness.

He could never really be angry at any of his kids.

However, it was really an interesting place where Obito had landed them this time.

The future of Konoha? Or was it an elaborate genjutsu the scroll conjured upon activation? The people here seemed wary of them, and he could tell Obito and Rin were happy to believe the time travel explanation, but real life wasn't as simple or complex as that.

So, in return, Minato would trust but not-quite believe these people. This older Kakashi, whose body language spoke of horrors he'd endured, or the mini-Minato, who despite looking only a few years younger than himself, spared no recognition (though the voice in the back of his mind whispered Protect, keep him safe. )

He'll play along until he could get everyone home.