Yes, ic2 experimental exists on 1.19 https://jenkins.ic2.player.to/job/IC2/job/1.19/.
It is generally not possible to seamlessly port worlds across minecraft versions due to the numerous changes they go through when porting. Blocks and items that existed in the mod in 1.12 may not exists in 1.19 and vice versa. You're also not getting any of the new vanilla worldgen changes either. Porting worlds across versions is not recommended and will likely result in world corruption.
If you want to start playing a new mc version, especially when the difference is this huge, you'll have to start over.