At last year's Google I / O, Google announced that the Android Pie beta would not only be available in the Pixel range, but that different manufacturers would also be included in the beta phase, but not all of them, only on the devices that were initially part of Project Treble.
Project Treble is the project with which Google wants Android updates to not take so long to reach compatible terminals, since it is the company that is responsible for driver compatibility of the different components that are part of the devices, being the task of the manufacturer to adapt the interface.
Although Project Treble seems to have not had the expected success from Google, at least it is what hints at the poor adoption we've seen of Android P among different manufacturers, the search giant plans to expand the number of companies that will be part of the Android Q beta.
According to Iliyan Malchev of Project Treble, the number of companies participating in the Android Q beta is even higher than last year. Malchev has made these statements to the Android Developers podcast, (chapter number 110 in case you want to listen to it).
Malchev does not mention the exact number of manufacturers that will be part of the project this year. The previous year there were 7: Essential, Nokia, OnePlus, Oppo, Sony, Vivo and Xiaomi. If Samsung or Huawei joined the project, it would be the accolade that this project really needs so that Android users stop being forced to wait several months to be able to enjoy the news that nothing new version of Android offers us.
For now, we will have to wait at least a couple of months to see which will be the new manufacturers that join this Google initiative