The Rootless Pixel Launcher had surfaced on the Play Store at the end of last month under the 'Rootless Launcher' name, but it didn't stick around for long, as Google has removed it from the Play Store already. So, it seems like Google removed this launcher for a rather odd reason. Rootless Launcher comes with Google Feed integration, but you'll need to install a companion app in order to use it, similarly to Nova launcher and Action Launcher, but unlike these two launchers, Rootless Launcher prompts you to sideload that app from an outside source… and that seems to be the reason Google removed it from the Play Store.
In the case of Nova Launcher and Action Launcher, you're not prompted to an outside source to sideload a companion app in order to use Google Feed, while Rootless Launcher basically prompts you to its installation directly, to a third-party source, and that seems to be a violation of Google's Play Store guidelines. The developer behind Rootless Launcher, Amir Zaidi, decided to comment on all this, and he has confirmed that apps that cause users to download or install applications from unknown sources outside of the Play Store are prohibited, according to Google. He added that he'll need to find a way around it, as he cannot use the Bridge installation pop up as is the case at the moment. He said that his 'package name' is banned, so if you decide to install Rootless Launcher again, after it becomes available, you will need to set up everything again.
Amir Zaidi says that he's working on a fix as we speak, and that the launcher will be available via the Play Store in the near future, once again. Rootless Launcher is still available via GitHub, where it has been available before it hit the Play Store. All in all, this doesn't seem to be such a huge problem for the developer, and is a thing that he can fix via a workaround, so if you do like Rootless Launcher, it will probably be back soon.