I mean, if an agressive civ is playing Authority then they will always be agressive for no reason from the start.
I've played 3 games on 5.0, one with The Huns on Emperor, I got attacked by The Zulus but the AI was broken on 5.02 so I easily conquered them.
Then I played Egypt on 5.03 again on Emperor, surrounded by Marocco, Korea and Sweden, Korea was closer to Sweden than I was, so they went to war multiple times and I got a chill start, and then Sweden was so weak that we split it in half with Korea, both Marocco and Korea wanted to be friends until I got a score lead. Korea even paid a huge GPT to declare war on Sweden.
Then I played Venice on Immortal, surrounded by Poland and France, there was no place for a city between Paris and Venice, we were that close, but France decided to attack Polynesia, and I again got a chill start, both Poland and Polynesia wanted to be friends with me until I conquered weakened France and got a score lead.
So in my experience everything is as usual, warmongers attack everyone, everyone hates warmongers, you can even get 2-3 cities from them without anyone getting too upset about it. And then everyone hates you when you are a leader. Also if you have army smaller than their, which is usually the case, they are more likely to attack you.