Google is cleaning house starting on August 1 2019 it will no longer accept new apps or app updates that do not support 64-bit processors. You will still be able to download the old versions of those apps, however. Note that games built with Unity 5.6 or older will be exempt from this and can still be updated.
There’s a way around this – 32-bit only apps can be updated, but they won’t run phones with Pie (of which there will be plenty after the MWC). This makes it less likely that developers will be willing to put in the work.
64-bit transition timeline
Also, from August 1 2021 Google Play will stop serving apps without 64-bit support. Thats for new phones, old 32-bit only phones will still be able to download the apps, though we have to imagine they will be terribly obsolete by then (the 64-bit switch-over happened in 2015).
Wear OS and Android TV devices will not be affected by this change as those are stuck on 32-bit for now.