If I'm not mistaken, iCloud does not sync apps and their content, only documents. From what you describe, this iCloud activity is not related to Logic per se, because you have already installed the app and are using it to download sounds. Just in case, I'd recommend to log out of iCloud in System Preferences to stop syncing your Mac while you're downloading Logic's additional sounds.
If I'm not mistaken, iCloud does not sync apps and their content, only documents. From what you describe, this iCloud activity is not related to Logic per se, because you have already installed the app and are using it to download sounds. Just in case, I'd recommend to log out of iCloud in System Preferences to stop syncing your Mac while you're downloading Logic's additional sounds.
Are you sure it downloaded to iCloud? That's not how apps purchased through App Store are normally being installed. Have you checked Applications folder on your Mac?
I think so, this is what happens when I try to download sounds. I’ve only had my MacBook for less than a week so there’s no way I’ve filled up the storage, and my Mac keeps opening the iCloud folder telling me to make space there.
Logic Pro x downloading onto icloud