I'm with you... seems fishy. This seems like an attempted fix due to a quality/design issue. A ballast should not trip a GFCI. They do generate high voltages but if it is works properly it should not allow current to flow to ground. They may be right on the edge for electrical insulation where it leaks more than 5mA but less than 15mA in which case their recommendation would work.
Not a fan....
this was my exact thought.