Zig's take on comptime is slightly different from C++ and D, but that doesn't make it revolutionary. It has first class types, which allows you to pass them to a function along with normal function parameters, instead of having a separate syntax for it like C++ and D. But it's not really new.
That's a little like saying that smartphones weren't really new because we had mobile phones and calculators and cameras and video cameras and handheld games before.
Zig's comptime is revolutionary and really new in that it replaces many other separate features and is the basis of Zig's minimalism. Figuring out how to discard features is much more difficult than adding them, and simplicity is something that's impossible to add once it's lost. The message is not the existence of a rather general compile time execution, but that with a particular design of such a mechanism you can do away with other things.
