Yet it would be ridiculous to claim a privacy advantage by doing this move, since the only change here is sending your browsing activity to Apple instead of Go

Yet it would be ridiculous to claim a privacy advantage by doing this move, since the only change here is sending your browsing activity to Apple instead of Google. And the Safe Browsing stuff is already kinda high in the "anonymized" scale anyway, up to the point Mozilla uses it. If they wanted to claim privacy advantage, they could offer these lists for rsyncable download, like antivirus of more civilized eras used to do.