Google is already working on the fourth generation Pixel handset, which is likely to be launched in October. This means that it is simply too early for pixel 4 leaks, although we know that the handset will run Android Q out of the box. And a revelation a few weeks ago said that Android Q would receive built-in 3D face recognition support, which made us wonder that Pixel 4 might contain Google's answer to Face ID. Meanwhile, Google has apparently confirmed a Pixel 4 feature already, thanks to an updated Android Open Source Project (AOSP) Gerrit. It's not too fancy, but it's still a feature that some people will appreciate.
As you can see in the following screen, Google plans to get better dual SIM support for 201
If you are a Pixel 2 or Pixel 3 user, you already know that your phone comes with dual SIM support out of the box, but one of the two SIM cards card is a virtual or eSIM. It's a handy feature to have in a phone as long as your carrier supports eSIM.
Pixel 2 and Pixel 3 phones support Dual SIM Single Standby (DSSS) technology, which means you cannot receive calls or texts on inactive SIM. In comparison, other Android devices and the latest iPhones support Dual SIM Dual Standby (DSDS) technology that allows you to receive calls and texts on either SIM card. Finally, there is Dual SIM Dual Active (DSDA), where both SIM slots can be used for calls, texts and data simultaneously.
Pixel 3 could support DSDS in the future but not DSDA because it lacks a secondary radio. But the new additions to AOSP seem to indicate that the Pixel 4 phones will have at least DSDS tech on board, which is similar to what other devices can do, including 2018 iPhones.