Is there a method to see changes to the Packages over time?
However, it would require System Backups were running on your server, and are available.
First, you want to see your current Package information. You can find it as flat files in the following location:
Example Package List name: cptest1
Package Directory: /var/cpanel/packages
# cat /var/cpanel/packages/cptest1
Then, you would need to view the same file from an older System Backups.
Example System Backup File: /backup/2020-08-16/system/dirs/_var_cpanel.tar.gz
You would extract the 'cptest1' file from _var_cpanel.tar.gz. If needed, reference the following article on how to retrieve it.
How to manually locate and extract a file or directory from a cPanel backup
At this point, you can compare the current Package file to the extracted data to find differences.