I’m guessing an AEW radar suite would require similar bandwidth to an MQ-9’s HD FMV plus other data, but that is a guess.
According to wikipedia, the MQ-25 is testing carrying AGM-158C munitions with a newly mounted E/O sensor ball, so the Boeing execs are at least thinking about BLOS ops and other uses for the Stingray. The LRASM weighs over 2,700 lbs per wikipedia so the lift is apparently there with the MQ-25’s Rolls Royce engine for a mini dome of similar weight.
The dome is only part of what the E-2 carries, the fuselage is stuffed FULL of equipment needed for the radar. And your bandwidth presumptions are likely WAY off the mark.