Here is a thing. The endpoint gs.apple.com already supports HTTPS (and on port 433). In fact, a new cert was issued to that endpoint on 23rd Feb 2022 -- before the date of your article. Something was already afoot before you wrote about it. This new cert also contains a custom OID, which could be used for pinning.

It is possible, with an http proxy / pihole to upgrade all of your local network connections to https when speaking to gs.apple.com.

My guess is that a change is coming, but the pieces aren't all in place yet.