Not a bug. It was how it was designed way back then.
They changed it to try and influence player behavior by the Alliance. But yeah, it’s as you said, too little too late for that.
They can still be skipped by running up from underneath the bridge, hope the GY guards doesn’t daze you, then run across the bridge to behind the south DB bunker and then around. It basically sets you in the same path as the ones exploiting the backdoor used, where it’s possible to avoid pulling elites.