If you want to move a ModPack to a newer version of Minecraft, you need to start all over. Add an auto-helper that will do as much as it can automatically - any mod with a version in the new version will switch automatically. Any mod that has set itself an alternative in that version will ask for permission to make the replacement ("Allow the mod creator to give alternatives to his mod in other versions/unsupported versions" idea). And once a new version for a mod that was in the previous version is updated, it will ask you if you want to add it as well. There should also be an option to create the new version of the modpack in a new profile.
This idea is mainly for people who create their own modpack on the computer and do not use the big release.