Unfortunately Asus took a standard royalty free connection type (Oculink 8i) and moved some stuff around to make it a Asus only product with no hope and the standard going anywhere. Even if it was OK by Asus, the bandwidth is double what the thunderbolt controller on the framework can process, so it just wouldn’t work.
The real problem here is everyone was all hopeful that Thunderbolt 3->4 will be a big bandwidth increase but that just didn’t happen so eGPU’s are just becoming a worse and worse tradeoff.
Fortunately a few hours ago, an Intel exec tweeted out a photo (and then quickly deleted it), showing that TB5 will be the 80Gbps everyone hoped TB4 would be. I don’t think eGPU’s will be a good bet if/until then.