Major decisions and events should be discussed as they occur. They are, y'know, major. Why would major things be the thing you wait and see, instead of minor things that may or may not occur?
If there are concerns of any sort in a case like this, they should be brought up immediately. Were people to wait, it would become "why didn't you say something sooner?".
I feel like there should have been an announcement of a successor, as has been established, and there should have been some discourse started by the team as yto Yui and why he was chosen. The memberbase shouldn't have to ask for explanations for a major decision.
No one is even calling this a problem, and no one is trying to cause drama with this.
Suggesting that people, who are amicably asking for the explanation that was expected, should simply wait until they're proven right/wrong doesn't really do PR justice.
Not to mention that this happens with literally any major event. New presidential election? New game trailer? New music album? Major things are discussed as they happen, not once they've settled in for a while and taken a foothold.
The last line also bothers me, because it's more "you're not a mod, so what do you matter". The language used suggests that member input is take it or leave it, and that only the team matters in the end. The team is here to moderate the site. I disagree with an election, as well, but that last point is not well articulated.