It clearly seems that they put in place some kind of a "queue" and then massively approve accounts once in a while (always on Thursdays and Wednesdays). Maybe the team working on that only works these days of the week :D
Thanks for the picture, I have never seen it. Is it in one of your reports or is it someone else's ? I would love to keep an eye on that.

I don't understand the goal of that. If no account is refused and no verification is done, why not instantly activate accounts ? It's kinda like shooting yourself in the foot in terms of retention.