On second thought, maybe the modern Egyptian style isn't so much a new innovation as taking something that was considered an outlier by the foreign/student BD community and making it the mainstream.
My personal belief, based on a survey of one, is that the "high end" modern Egyptian we've seen over the past 30 years or so has been a combination of folkloric footwork patterns and beledi body work, plus various innovations that individual dancers have brought in, and that others have picked up on and used themselves.
And yes, I think you're right. Have you SEEN ghawzee and awalim footage? It aint that different to what these women are doing (the ones in the second clip are quite lovely IMO, and there's nothing wrong with a shimmy. Unless the concern is that the dancers are also fat and therefore have "vibrato" that way?)