Perhaps it should be noted that Rod Roddenberry is an Executive Producer on many of the new Trek shows, and he is fine with his mother's voice being used if they so desire.No one's going to be making any money out of Majel's voice being used. It's a nod to her history with the show.
I very much doubt it would attract even one extra viewer / advertiser / sponsor.
Not all uses of likenesses and audio samples would be so benign, and there does need to be regulation and oversight, but this wouldn't be in any way a cash grab.