I mean, that would make sense. But being Google, I think they're likely to name it something different that nobody recognizes. And then change that name to something similar enough to ChromeOS to cause confusion, since they're actually separate and incompatible products.
Sigh. Sorry, I used to work for Google, on chat and video chat products.
There is zero chance that Zircon will be faster than Linux.
The classic example is Mach from CMU:
"When Mach was first being seriously used in the 2.x versions, performance was slower than traditional monolithic operating systems, perhaps as much as 25%... When Mach 3 attempted to move most of the operating system into user-space, the overhead became higher still: benchmarks between Mach and Ultrix on a MIPS R3000 showed a performance hit as great as 67% on some workloads."
https://docs.sel4.systems/projects/sel4/frequently-asked-que...
That is why QNX and INTEGRITY have no sales.
Linux performance is so beyond what everyone else can achieve that is why nowadays we run it virtualized and pack applications into containers.
Either way, it doesn't matter, I'd expect whatever is running in ChromeOS (Linux Kernel) to be replaced by Fuchsia (Zircon kernel) underneath. They will more likely keep the 'ChromeOS' name to limit the confusion and that will be what these devices like that $100 Chromebook will be running in the future.
So it will be even more locked down and tightly controlled.