Andrew, I know you read these threads sometimes, give us a sign so I can go down the mountain with my stone tablets and tell the people whether we'll have coroutines
While Andrew has the final say, as Loris points out, we always work to reach a consensus internally. The article lists this an an implementation that will probably exist, because we agree that it probably will; nobody is promising it, because we also agree that it isn't guaranteed.
Also, bear in mind that even if stackless coroutines don't make it into Zig, you can always use a single-threaded blocking implementation of `Io`, so you need not be negatively affected by any potential downsides to fibers either way.
This new `Io` approach has made it strictly more likely than it previously was that stackless coroutines become a part of Zig's final design.
Disclaimer: I'm not actually a Zig user, but I am very interested in the design space.