yeah, the 4-3-3 is a Blanc leftover, the players were more familiar (at home) with it, that's why he went back to it, I think. Verratti in particular likes that formation because he's allowed to spread his game over two different key areas for PSG.
I don't really know what an Emery side looks like, I've seldom watched Sevilla while he was there, but this Paris side looks uninspired and extremely pragmatic in comparison to what it once was. I stopped watching them when he decided to drop Trapp, that was the last straw. From what I've seen so far Emery looks like the kind of coach who prioritizes his plan before his players, and I despise that. To me a good coach should always look to make the best of his players, not shoehorn them in pre-made concepts.