The GFX100 looks like a killer camera for anyone shooting portraits, weddings or anything in that vein, which is a huge chunk of the professional photography industry. The two GFX50 models gave the full frame tree a shake but this should really cause a major wobble in the market. Fuji have been ballsy in this venture into medium format but this camera could be where they see their real pay off, especially because they have a major leg up on the competition who have been busy clubbing each other with full frame.
I'm not the market for that camera. I'm not a working pro and I don't have the money for that kind of treat, but this camera could, and should, be revolutionary in the professional world - especially with what looks like an increasingly small, professional market for camera sales now that casual photography moves steadily towards mobile devices, I can't see why one wouldn't want 100mp medium format with IBIS and eye-AF with tracking.