FWIW, my conversations have (to me) painted a different picture around the future of kernel extensions: it seems like they will only continue to exist until the last large company that relies on them doesn't have a userspace API replacement. The remainder seems accurate, but I would really love for Apple to allow me to put up the guardrails again but in a way that I control…
That has been the official message at all WWDC talks since userspace extensions have been introduced.
Actually I look forward to it, eventually Linux and BSD will stand alone as the only classical monolithic kernels, which is kind of ironic, given how much containers and hypervisors they get loaded with anyway.