It is, and has long been, very hard for any player to look good playing for Schalke, as the club has dysfunction seeping into the team from everywhere around, so you're right, and one should not hold anything that happened there against McKennie. And good on him too for getting out of there, and getting this great move no less.
I always considered him a kind of defensive midfield workhorse player at Schalke, but it seems Pirlo is using him now in a more attacking position, or how would you describe the position that McKennie can now focus on, as you say?
(I've watched a few Juventus matches in the beginning of the season, think McKennie started the first league game in DM, but I haven't been able to watch any of the recent matches)