Last year, when Google released the Android P beta, Pixel and Nexus handsets were able to download it. Being Google phones, that was to be expected. But Google also partnered with other manufacturers, allowing seven different non-Pixel or Nexus models to receive the beta builds of Android P. Those devices included the Essential Phone, Nokia 7 Plus, OnePlus 6, Oppo R15 Pro, Sony Xperia XZ2, Vivo X21 and the Xiaomi Mi Mix 2S.
With Google I/O 2019 starting on May 7th (and running through May 9th), the thoughts of Android users will soon turn to Android Q. Google developer Illiyan Malchev, who heads up the Project Treble team at Google says that Treble was the main reason why so many non-Google handsets were able to install the Android P beta last year. This initiative has made it faster and easier for Android phones to process software updates.
And this year, according to the developer's comments on the Android Developers Backstage podcast (via XDA), we will see more non-Google phones get a crack at the Android Q beta. During the podcast, Malchev that he can't reveal the exact number, but it will be more than the seven phones that supported the beta last year.
It was exactly one year ago yesterday when Google released a timeline for the Android P beta that started in mid-March with the alpha release of Android P. Hopefully, we will see an updated timeline released soon for Android Q.
Keep in mind that just because your phone might be able to install the Android Q beta, it doesn't mean that you should install it. Beta software is buggy and unstable. If you rely on your Android handset, most likely you will be better off awaiting the final, stable version of Android Q.