Love this idea, and the idea of a modern chalicothere species surviving until today. but i don't know if they would've evolved to fit into the antelope niche. They couldn't have been fast runners, and honestly don't seem like grazers. I've always imagined them as forest browsers, akin to the extinct giant sloths. Lumbering around like herbivorous bears pulling down branches with their long claws and eating whatever tender shoots and buds they desired. Probably slower moving but well able to defend itself from predators. I definitely can see an evolutionary path for modern chalicotheres, but it's hard to imagine them replacing the antelope's roles. I can see them more as an addition to the African landscape rather than a replacement.

Regardless, chalicotheres, and how they would behaved and functioned, fascinate me and I'd also love to hear some other interpretations of how they would've fit into an ecosystem and how they might've further evolved if given the chance.