It's worse than that: a default macOS install with Safari will re-open Safari, complete with re-opening the tab that was open upon a hard power off and power back on.
So to get it to stop doing this on restart, I had to be very quick to force-quit Safari as the machine rebooted. You don't get a chance to tell it "Don't reopen all windows" when you hold the power button down.
So to get it to stop doing this on restart, I had to be very quick to force-quit Safari as the machine rebooted. You don't get a chance to tell it "Don't reopen all windows" when you hold the power button down.