Which is a forked descendant of WebKit, so GP is right or wrong depending on how you classify a fork.
In reality Blink diverged significantly from WebKit and it doesn't make any sense to call Blink WebKit.
It seems like if things keep going this way, Safari also would inevitably end up rebasing Safari onto Blink too (with their strategic changes).
I'm not sure about that. WebKit is lagging slightly behind Blink (and Gecko to lesser degree), but I don't think it bothers Apple. Budget to develop WebKit is for Apple hardly a problem as well.
Having independent browser engine gives them quite a lot of strategic power given their exclusive market share. Look no further than how they managed to single-handedly kill PWAs few months ago since it does not fit into their strategic goals (all apps must go through app store).
I'd expect them to maintain all strategic decisions if they did refork, including disabling PWA features; there's nothing that says they have to enable PWAs just because they fork from Blink.
Because I was scanning around to get a lay of the browser engine landscape and there seems to be tons of Safari traffic out there.