Looks like they released them in the PBR format (not the specular-glossiness) format some time ago. From my 5 minutes of messing around of them, some still look a bit off. Luckily, it’s just the roughness maps, which aren’t a big deal. Maybe because it’s the differences between PBR and specgloss which I’m not educated about. But yeah, here it is.
https://create.roblox.com/docs/building-and-visuals/studio-modeling/materials