Back in 2015, Android added support for 64-bit apps with the arrival of Lollipop. 64-bit apps have been supported, but they haven’t been required. Plenty of apps are still 32-bit. Google is looking to change that in the future. Android apps will be required to support 64-bit code by August 2019.
Apps don’t have to ditch 32-bit completely. They just can’t exclusively support 32-bit. Google says there will eventually be devices that only support 64-bit code, so this is a way to prepare for the future. In August 2018, new apps will be required to target Oreo’s programming interface as well. This doesn’t mean they will require Oreo, but they will have to adapt new features.
It’s not exactly clear what will happen to apps that don’t support 64-bit. There are tons of apps in the Play Store that haven’t been updated in years. The Play Store will look a lot smaller on a 64-bit device. The good news is developers have plenty of time to add support. We have one and a half years until the big deadline.
[via Google Dev Blog]