If the OS is structured properly, there is no reason for the core OS and drivers to have to be shipped in lock step. With a well defined interface and separation of the binary image, development and release could occur independently. I hate to say it, but that is a key advantage of the RO5 HAL model, which should have been at least replicated in the RO6 work instead of sticking with the single ROM image and module chain.
As for emulation only, that assumes that the RISC OS environment will never be able to interface to any new peripherals, reducing it to a dead OS and mere toy. If emulation has any future, RISC OS must make direct use of equipment such as scanners, webcams and other USB kit in the same way it can currently use the hosts networking, without having to drop back out to the native environment and use non RISC OS software - otherwise that's where they'll stay.