No, and, in fact, I specifically said that C has unparalleled tooling in the formal verification space: https://news.ycombinator.com/item?id=24618856
But, 1. as much as I like formal verification and am actively involved in the space, we're talking less than 1% of C code that uses those tools (unfortunately), and 2. because Zig is so simple -- simpler even than C from a formal analysis perspective because of slices and casts -- if it ever becomes successful, I have no doubt we'll see such tools emerge.
Of course, the other 99% can't use Zig either because it's not even "out" yet. Obviously, a product that doesn't even exist yet can't replace any product that does, and no one is suggesting that Zig -- in it's current virtually nonexistent form -- is a replacement for anything, let alone for C. We're talking about what Zig could do when it exists in some production-ready form.
Are you sure you hit all the execution paths during development?
Pervasive casts? Not under MISRA C.
Look, I'm not criticising Zig on a technical level (I mentioned above I'm keeping an eye on it because it looks interesting), but I don't have any trust in community driven languages keeping it simple (although Zig promises to do so, see link above).
EDIT: Corrected formatting.