The reason Microsoft wants you to convert this is to drive sales, mostly. Secondly, for compatibility. Thirdly, it makes functions more secure against buffer overflow attacks. I bet the author cares little for these things, especially if the scope of the product has changed. It goes back to that issue I was talking about. All the design documents in the world are not going to help you when it comes down to changing the product itself because the audience changes or the purpose changes. There is a finite amount of time in this world, so you can't make everything hyper-flexible. "Well you should have done that in the design document" is tantamount to saying, "You should've thought of that beforehand." Just as helpful, too.
If Aurora amounts to sales, I'm sure it will change his mind, but I doubt he is going to chase after an unknown foreign audience.