Linux apps for Chrome OS may show up in stable channels of the system as early as the update to version 69, according to a subreddit associated with the project. In fact, it appears to have initially been slated for even earlier release in Chrome version 68 but just missed the cut-off. That's based on a series of commits which suggest that a review which would apparently finalize support for the apps, posted under the umbrella of Project Crostini, is only a few weeks away from "stable" Meanwhile, Chrome 69 is slated for release on September 4. That's just after the review mentioned above is set to be completed and has led to some strong speculation that the two will ship out to Chromebooks together. The update will almost certainly hit Google's own Chromebook first. However, that's not necessarily going to be the case here.
For now, Linux app support is already available on a reasonable number of Chrome OS laptops via the Dev Channel of the operating system. That includes Google's Pixelbook and HP's Chromebook x2. However, that's a strain of the software that is intended for use by developers and is inherently unstable as a result. Support on the Stable Channel will pave the way for use on current and future devices for any user with compatible hardware. The introduction of Linux apps into the Chrome OS ecosystem should allow users to go far beyond what's possible with either web or Android apps. In effect, it will bring the operating system much more in line with traditional desktop environments and allow for the use of more desktop-like features and software while bringing further open-source aspects to the mix.
The latest Chrome browser, meanwhile, will almost certainly arrive for other devices first, as it traditionally has. Chromebooks and mobile generally lag behind by close to a week and sometimes more while Windows machines, Macs, and Linux get support first. That should place Linux support on Google's browser-based OS for arrival on or around September 11. With that said, there's no guarantee it will ultimately arrive by then since there can always be unforeseen complications when adding to the capabilities of an operating system.