Did the talk offer any solutions to this? Its not like any of the secondary processors he could be talking about have any kind of open source support or even public specifications of their programmability or ISAs or similar.
The solution, and one that he specifically calls out, is that operating systems people need to work with hardware people to build better hardware and software together to build new computers. We got into this situation because everyone was just solving problems with the tools they readily had available to them. This is obviously easier said than done, but it does make now a very interesting time to work at one of those handful of large companies which produces their own custom SoCs and operating systems (I believe it's Apple, Google, and Microsoft) since you really have to take both operating systems and hardware forward simultaneously to solve the underlying issue.
What I understand - currently there is not even a model of an "operating system" as such that would even consider those secondary processors.
The appropriate model would be exactly the one described in the original article above - explicitly treat the computer as a network of devices, and have the OS on the main CPU acknowledge that it is effectively sending a message to e.g. RAM over a shared network that also contains multiple other devices, potentially untrusted.