That was definitely fusion, both of music and dance, but I don't think that's where the CONfusion began.In LA, NY, and SF, in the 60's and 70's, where you had a melting pot of Greek, Lebanese, Syrian, Turkish, Egyptian, etc of musicians/dancers performing together at clubs and other venues - the start of "American Cabaret". Out of need and demand, ends were pulled together to create a supply, and in that supply stream, a fusion began...
I think the ballet influence might have delineated Folkloric style from Oriental, but not really classical from modern. According to Shareen el Safy, once Badia stuck the dancer on a stage and presented the dance as a stage show, that's when Raqs Sharqi was born out of the folkloric form. Shareen credits the ballet posture and uplift as opening up a new way of moving, but that was in place by the time the "golden era" started.Or how about that influx of Russian dancers into Egypt and Turkey? That influx of ballet which creates the lines between "classic" and "modern" Egyptian for some?
If you look at folkloric side by side with Oriental you can see how the posture affected the way the movement looks, but I don't think you can really call the upright posture a fusion of ballet with belly dance.
The mass influx of dancers NOW from Russia is due to the collapse of the Soviet-supported arts. The unemployed dancers found job opportunities elsewhere. I don't see them as having really any effect on the Egyptian/Turkish dance itself (you could argue they affected the economy, but that's a different subject.)
As for Bal Anat -- that's a good question. It's hard to say exactly what was going on in the US, because different things were happening in different places at different rates. I don't know that I would call Bal Anat a fusion though. But I've only seen the remixed show and about 20 minutes of footage of the original group.