I think with lots of things, there is not enough volume and cost relative to personnel to justify the R&D and ongoing operations. For quite some time you would still need an operator and there is always the edge cases that a human can deal with on the fly that the robot cannot.

Bottom line, the world needs a finite number of plane refuelers and they are cheap. No need to replace them anytime soon.

But yes, technically possible at this point, I would agree.