It looked like Freightliner had manufactured it the way it was. There were no holes covered up where mirror mounts should be.
It didn’t seem to be some sort of special test truck. It seemed to be a working truck belonging to Nussbaum.
The cameras looked like the ones I’ve seen on Maverick’s trucks. But they still have mirrors.
I recall reading some of the press reports about Tesla delivering their semis saying that they want to ditch the mirrors but decided against it because it wouldn’t be legal.
[Edit] Company that makes the cameras announced they received a 5 year exemption to FMCSA rules in 2019. https://www.stoneridge.com/2019/01/02/fmcsa-approves-exemption-for-stoneridge-inc-s-mirroreye-camera-monitor-system/
[Edit 2] Just saw a second Nussbaum truck without mirrors. This one did have holes covered where the mirrors were removed

