"Continuity of Government" is the term used for "permanent control". Even under a nuclear attack, funded by the proles but provoked by the ruling class, the ruling class already has plans to remain in control over whichever proles remain alive. They have shelters, paid for by the proles. The proles, of course, do not have any shelter.

But that's old world thinking. Munitions cause so much damage to infrastructure that having control over the proles would be meaningless as there wouldn't be enough proles to rebuild necessary facilities.

The current thought is that the proles are indeed useful as lab rats, but of course they need to be restricted as to movement and diet and homogenized as much as possible to make the data useful. Once the experiments are over, the proles may be disposed. Once the proles furnish enough robots to keep the infrastructure working, the proles become useless and can be removed.

"Continuity of Government" is simply "continuity of the ruling class". Proles are expendable. A plane landing in a neighborhood is acceptable. But any attack, threat of attack or even seeds that may become a threat to an attack on the ruling class must be stamped out immediately. A false flag "pipe bomb" in the neighborhood of a ruling class building falls under "Continuity of government". But arson destroying the property of thousands of proles is simply unfortunate.