True, but I find it hard to believe that they would go to the trouble of changing the grind and running just these blades (time, cost, effort, etc.)No, but unless you can get Gillette to tell you which blade they rebranded, trying to determine which one is experimental guesswork.
And it's even possible that they took an existing blade, rebranded it, and changed the grind angles. That would change the feel of it.