That's exactly how Torreira played in Italy. Pressing high, driving the ball up the field. Was always a Ramsey substitute rather than a holding midfielder. Emery's shittiness as a manager reached new levels for sure when he decided to play him as a #10, but Torreira has never been a player who sits.
The only thing that changed is that he went from having one outstanding attribute - his Kanté-esque ability to run for two people all game - to having no outstanding abilities whatsoever. Tank was empty after four months in England and never got refilled, and he has looked like the bang average footballer he is ever since then. I know people who mentioned PEDs were probably joking, but it really makes you wonder.