The Fujifilm GFX100RF is right around the corner and it will be interesting to see how it does. It will either be impossible to find like the Fujifilm X100VI or miss the mark which could be a setback for Fujifilm. The retro camera scene is huge, but I am not sure that it can absorb a $5,000 camera the way it has sucked up all the X100 that Fujifilm can produce.
If the Fujifilm GFX100RF does not sell well I believe that it will be the product of two errors. First Fujifilm should have preserved and improved the hybrid viewfinder from the X100VI and second Fujifilm should have created a faster lens with f/2.8 being ideal and f/3.5 being acceptable. Focal length could also be an issue, but that is always the case with a fixed lens and Fujifilm could release adapters like they have for the X100 in the future.
Fujifilm GFX100RF: B&H Photo / Amazon