No, the Read part is whether the LB's drop out. If they drop into coverage he releases and Rosier has to be on the same page and take off running.
If the LB's step up, or blitz, Gauthier stays in to block and they're running routes to combat this. Gauthier isn't releasing immediately because he's reading what the LB's are going to do.
One of the things I always want to get across in my film review posts is that this offense is setup to counteract whatever the defense wants to do. Play tight man, we run square-ins, seam routes, deep stuff. Play zone we run combination routes and just abuse your LB's in space. Play coverage with your LB's immediately, we run with our QB. Play off to prevent the slants, square-ins, and deep stuff and we run bubbles on you.
There is an adjustment to everything you're going to do as a defense. It's all reading by the QB. When he was at Florida State I wrote a piece on his offense and you could see the "read" at that time was whether to be in shotgun or in I-formation and it was all predicated by what the defense was doing schematically based on the number of defenders in the box. We've evolved, but it's still the same basic concepts coming to life.
As you've also seen, we tend to have variations we can employ off of each formation variation. It's great stuff and incredibly hard to defend when we're running it correctly.