I know IndustrialCraft2's last version is on Minecraft 1.12.x(Cross-version between 1.12 ~ 1.12.2), but Minecraft currently is on 1.17.1(including the OFFICIAL copper ore and ingot).
Maybe it's hard to know right now(for me) but the latest release is at Oct. 2020.
So... Please let me and us know which version is in development
* If you're talking about Minecraft 1.16, than 1.16.2 and later release should be called differently because there's new items and mobs. Forge mods mostly don't support cross-version support between 1.16 ~ 1.16.1 and 1.16.2 ~ 1.16.5.
* Also, If you're talking about Minecraft 1.17+, than please let us know if you've changed copper ore spawn policy.