One nice thing about this feature (for Apple) is that it now allows Apple to get something it did not have before: usage statistics. Granted, Apple Software Update enabled Apple to see how many people were updating their Boot Camp drivers, but it was a poor measure for how many Boot Camp installs were actually being made.
Anyone in the industry will tell you that people often don’t update software. In addition, those downloads were homogenous; you could download a Boot Camp 1.x, 2.x, or 3.x update and deploy these across thousands of systems with a single download. The Boot Camp Assistant pulls down different bundles for each system, requiring it to be done on the computer, and having the computer pull that file down from the web.
As such, the Boot Camp Assistant is likely what Apple is using to keep track of how many people are using Windows on their Mac at any given time. And, it gives them per-model counts, so they can track how many, say, MacBook Air users are choosing to give up precious SSD storage in order to run Windows. Considering the bundles are model-specific, they could even be keeping track of how many people, for example, chose to install Windows on a 64GB MacBook Air versus a 256GB MacBook Air.
My point in conveying this information is that you should always re-download Boot Camp drivers with each Windows install. There is certainly a lot of interest in Apple (or at least, there should be) in evaluating which Mac models are going to be moved to ARM-based processors, and which will stay on more-powerful Intel CPUs. Windows support is a key factor in that, Apple does want to know if that feature is important to you (even if they have no interest in replying to your emails stating such).