Continued support for legacy Binary Provider API

As per Apple -

"All developers should migrate their remote notification provider servers to the more capable and more efficient HTTP/2-based API described in Communicating with APNs."

Though there is no 'must' here, you never know when Apple may deprecate this binary interface (Probably just how they deprecated VOIP BG Socket since PushKit is available). To the best of my knowledge, there is no such indication by Apple till now.

I have the same question after receiving the mail below from Apple the 09/26/2018

We noticed that your apps may be communicating with the Apple Push Notification service through the binary protocol. Since this is a legacy protocol, we recommend updating to the enhanced HTTP/2-based API as soon as possible. You’ll be able to take advantage of great new features, such as authentication with a JSON Web Token, improved error messaging, and per-notification feedback.

So what to do now ?

The Apple Push Notification service (APNs) will no longer support the legacy binary protocol as of November 2020.

https://developer.apple.com/news/?id=11042019a

"The HTTP/2‑based Apple Push Notification service (APNs) provider API lets you take advantage of great features, such as authentication with a JSON Web Token, improved error messaging, and per‑notification feedback. If you still send push notifications with the legacy binary protocol, make sure to upgrade to the APNs provider API as soon as possible. APNs will no longer support the legacy binary protocol after March 31, 2021." By Apple

Hi, how to know if you are using legacy binary protocol for APNs?

If your endpoint is api.push.apple.com:443 you are using the HTTP/2 interface.
If you are also receiving your notifications, then you are also using the correct protocol.