No it doesn't. Anything with sufficiently advanced technology to threaten a dyson sphere wielding species would probably detect the gravitational anomaly of th

No it doesn't. Anything with sufficiently advanced technology to threaten a dyson sphere wielding species would probably detect the gravitational anomaly of the missing star and go investigate there first. Taking a tiny portion of the energy from a bunch of stars seems wildly more efficient at surviving from a threat than putting all your resources into creating a system they're sure to investigate.