I really enjoy this Stig, though. Prop, schmop--the dude can drive and does very well at the kinds of nonverbal gestures that make up the character. Compare Usual Stig with Schumacher's turn at playing Stiggy. Sure, Schumi didn't spend much time with his helmet on for that episode, but even his nod "no" at the start of the interview wasn't...gosh, at that specific balance between over-playing it (nodding too hard to where it looks silly, as you might do to emphasize smaller gestures in stage productions) and under-playing it (being too subtle for it to translate well on TV--e.g. Schumi's nod). I know that's being quite anal, but it's something I've noticed. He's not just the guy who can drive fast--he's an actor, too.
I don't know the terms of the NDA or the backstory behind this move, so I'm going to reserve judgement until the dust settles a bit. I'm genuinely interested to hear his take on being the Stig, even if I'm disappointed that it had to come about like this.
So, back to speculation, then. It's been pretty obvious for quite some time that Collins is the main guy behind the Stig. It's been out on the Internet and there was a paper article "outing" him at least a year ago with that house painter/racing suit under glass piece, so it's not exactly a secret anymore. Could this have affected the terms of the NDA (for example, if it said that Collins has to go if anyone outed him at all, thus making his continued employment with the BBC one big grey area)? Could this have affected him in any other way, such as with his family or with whatever he's racing elsewhere? The last thing some team is going to want to hear is that they're short a driver because Stiggy flipped a Kia in the off-season.
Again, I don't know any of those details, so I'm not going to come down hard on the guy just yet. I hope TG keeps the character of the Stig going (even if they change colors again) despite all of this NDA weirdness, though, because he's one of my favorite TV characters...pretty much ever, honestly. The whole bit is wacky and wonderful and I love seeing all the cars get thrashed on like they should be. I don't even think it would matter if they kept Collins, so long as there wasn't any bad blood between him and the others on the show. He's been "outed" (albeit less publicly) for well over a year anyway.