If you look carefully the one without the tug bar still has the holes in the pickguard.
I don't know for sure but i guess it might be like the American vintage series, you receive the hardware and can choose to instal it or not.
Either way, if it comes pre installed just unscrew it, not a big deal.
The tug bar was never meant to replace a strap otherwise early basses would not have had strap buttons! There where put there because Leo imagined an electric bass would be played with your thumb and they allowed you to anchor your fingers while doing so.
Sting plays mostly like that.
When he realised more and more players played with their fingers, (in the 70s) he moved the tug bar over the strings and it was renamed a thumb rest.