Google seems to be testing a new version of its Pixel Launcher, according to XDA Developers. This new version, as you can see in the provided image down below, will bring a slight change to the Google Search bar, if Google opts to release it at some point, of course, because it's currently 'in testing'. As you can see, the Google Search bar includes a Google Assistant icon on the right, instead of the microphone icon that was available there before. Clicking that icon will bring up the Google Assistant interface, of course.
Now, if you take a look at the provided image, you will be able to notice that the version of this app is '9-4889482', while the latest version available online is '9-4836503'. XDA Developers said that the new APK will become available for sideloading soon, while the source also noted that it will not replace your current Pixel Launcher, if you decide to sideload it, as it will have a different signing key than the standard Pixel Launcher. The introduction of the Google Assistant icon to the Google Search bar was not the only change noted by XDA Developers, it seems like this new version will also make the icons on the search bar remain colored regardless of the currently-set wallpaper. It is still unclear when will Google start rolling out this version of the Pixel Launcher, or if it will happen at all, as this is only a testing period, as already mentioned.
The Google Pixel launcher has been available out there for a while now, and Google did release quite a few updates to it thus far, but never made some ground-breaking changes. Well, this new version, if it ever starts rolling out, will not make any such changes either, just a couple of small tweaks. It seems like the changes to the Google Search bar will be the only thing that Google will change in the new Pixel Launcher version, at least according to the source, but it remains to be seen what will happen by the time it officially arrived.