No.. you dont need to do anything..... as nothing has been corrupted.... that is, if all you are asking about is the new Alchemy plugin being missing in Logic Pro X...
Again, the only thing that has changed is that GB was updated and that update included a new plugin based on the older Camel Audio Alchemy plugin.
So, the new library presets that came over from the new version of Garageband will not work... because Logic Pro X has not yet been updated to include the new plugin based on the old Alchemy plugin... that those new library presets use.
Current solution?
Simply don't need to use those specific new library presets that were added when you updated GB... until the update to Logic arrives... They are new library presets so you are not missing anything from Logic that you used in older projects.... and everything you created prior to the GB update, will work normally.
If, however, you are having an issue with accessing the older Camel Audio version of Alchemy that you previously bought and installed.. now you have updated Garageband.. and you cannot access it...or older projects cannot load it in... then simply reinstall the CA version of Alchemy..... Make sure it is validated in Logic's Plugin Manager... and it will work again.