I’m not sure how you came to your conclusion but it doesn’t seem justified by the info in this bug. It reflects Web Push being done in WebKit by Apple engineer

I’m not sure how you came to your conclusion but it doesn’t seem justified by the info in this bug. It reflects Web Push being done in WebKit by Apple engineers (who use and pay attention to bugs.webkit.org). Apple doesn’t usually comment on when/if WebKit features will ship in Safari but Apple engineers don’t generally do stuff like this just for kicks.