They were, i have read that half of Corruption's team have remained at the studio and not only that: They poached from everywhere.
Just from the top of my mind - Dreamworks, Santa monica, all three call of duty studios, respawn, Naughty Dog, Bioware, ID (a lot from id), 343 Industries, DICE (a good amount), Eidos Montreal and Crystal Dynamics, Rockstar's executive producers, etc.
I think they doubled their size from a few years ago or are close to it; just last year they hired 25 people.
I think its super exciting that retro has been hiring a lot of writers, i wonder if that means Nintendo, in this decade, will release their first cinematic game.
Usually i wouldnt pay much attention to it as those games are very common within the industry but one published by Nintendo? Hella interesting id say