Apple today sent out a notice to developers urging those that continue to send push notifications with the legacy binary protocol to update to the HTTP/2-based APNs (Apple Push Notification service) Provider API as soon as possible.
Apple says that developers will be able to take advantage of features like authentication with a JSON Web Token, improved error messaging, and per-notification feedback.
More information on the Apple Push Notification service Provider API can be found on Apple's website.
Apple's Push Notification service will no longer support the legacy binary protocol starting in November 2020, so developers that continue to use the older protocol will need to update before that date.
Top Rated Comments
Apps won't stop working. Some might not get push notifications anymore, but most who don't migrate probably don't have them working anymore, anyway. This is only a server side change.
No they won't. At least not because of this depreciation: this only means that backend developers have to update their code.
Most already migrated to the new API, or use providers that have. This has literally no incidence on whether your phone can run an app or not, and it's nothing buying new hardware will fix.
It's sad when old apps won't work anymore because newer versions of iOS break them. Some apps are no longer maintained but still have value; these deprecations give apps an eventual expiration date. Other platforms don't do this as much.