Google is looking to shift from using Chrome apps to Progressive Web Apps once it stops supporting the usability of Chrome apps in its browser on PC, Mac, and Linux systems sometime next year, and while Google hasn't given a hard date on when exactly Chrome app support will stop on these platforms, it is supposed to happen sometime in the first quarter of the year which will be sometime within the first three months. While Google may not have intended to support apps in the Chrome browser on PC, Mac, and Linux at all after Chrome app support was to end, the advent of Progressive Web Apps seems to have have shifted Google's intentions and it makes sense as Progressive Web Apps are apps which can be used in more than just the Chrome browser, in addition to being compatible with more than one operating system.
Google sent out an email to developers which explains the state of PWAs and the way they'll be taking over for Chrome apps in the future. Google's plan was to stop support for Chrome apps in early 2018, but it's now saying that the complete removal of Chrome apps from the above-listed platforms won't be happening until the availability of PWAs are there, meaning users are able to install Progressive Web Apps onto their desktops. Once this is possible Google says it will be stopping the support of Chrome apps in the Chrome browser, though it still doesn't have a date, just a time frame of "some months after" what it originally had planned.
Since much of this will affect developers in different ways than users, Google is also looking into ways that it can help developers in the change from app type to app type, as it notes that it has recognized not all Progressive Web Apps will have the same functionality as a Chrome App counterpart due to the use of the specific Chrome App APIs that are only part of that Chrome App and wouldn't be available to the PWA. To that end Google is investigating ways to make things simpler for developers here. From the user side of things, not much should change. PWAs will be installable on desktops with launch icons just like Chrome apps, Google says, so that will still be no change on the user side.