TB4 supports DP2.0, which (in UHBR13.5 or UHBR20 mode) has enough bandwidth for 5K @ 120Hz (or 144/180 Hz with UHBR20).
The issue is more likely to be availability, and marketability.
In general the demand for high refresh rates on desktop displays is driven by gamers, far more so than resolution - it's pointless having a 5K or 6K display if your GPU can only render the game in a playable fashion at 1440P or whatever. This demographic is well known to sacrifice resolution for higher refresh rates. I guess a low detail image that animates smoothly is preferable to a high detail image that is jerky or looks like a slide show.
A large part of the buying market for high resolution displays (particularly above 4K in the 27-36" range) is going to non-gaming users, who are doing regular desktop work where 60Hz is likely to be fine. Most people aren't going to be able to type or draw or do much else productive fast enough to "defeat" 60Hz for practical uses.
I don't think it's a coincidence that Dell, ASUS, Samsung, LG and BenQ all have high-end displays shipping or announced, that explicitly mention support for macOS, and just happen to use a PPI that suits macOS' scaling "@2x" scaling mode perfectly.
Nor do I think it's a coincidence that the 5K@60Hz spec they mostly support is viable on Macs as old as the 2016 MBP15, from 8 years ago. Heck even a 2018 Mac mini with just an iGPU will do 5K@60Hz.
I'm not saying no manufacturers will support higher refresh rates, but realistically I think you're looking at a product that would be a niche within a niche. It's only recently that most of the above manufacturers have (re)entered the ~200PPI display market, it's going to take a while before there's enough potential customers for what you're talking about.