I've never been a fan of ATP's 90 day program. I think it pushes the limit since you have no time for seasoning between ratings. No time to learn "outside the box". So, in my opinion, "nobody can do it as fast as ATP", is more of a negative than a positive.
To answer the OP's question about the intern turbine time thing. I believe ATP has planned for a long time to operate a new model of the VLJ's (forget which one) in a charter or Frac type operation. They will need a fully qualified pilot for the left seat but will put an "intern" in the right seat to build turbine time. Depending on how this is structured, it could be seen as Gulfstream style PFJ, at worst, or simply loggable ride along time a la Eagle Jet International.
In the end, it's hardly proven how the industry will respond to such a unique program, even if there was any hiring going on for the industry to respond too...
In this hiring enviornment, I'd hardly suggest ATP "because" of the internship program. If you like ATP for other reasons, then knock yerself out, but I see the "internship" program as a highly unproven carrot that ATP is using to sell their program much like the RJ course used to be.