was wondering what happens with hardware drivers. Does this kind of tool for updating the system/apps keep also hardware drivers updated?
Drivers are either compiled into the kernel, or as kernel modules which can be loaded as needed.
If you current kernel doesn't include a module for some piece of hardware, then you may be able to re-configure the kernel and compile it to get the necessary driver. If it's bleeding edge hardware, you may have to upgrade the kernel to the latest release in order to have a working driver.
Some drivers may be proprietary and only available from the hardware vendor's website. Look for the driver package and installation instructions.