In the knowledgebase I wasn't able to find specific upgrade information like:
Currently in client X there are X objects using PREP_PROCESS_VAR: when upgrading from version X to version Y this has changed ...
Previously we had a service company that provided us with such a list for all our clients and we would be able to go through the checklist of objects. From what we understand this information was extracted from an automic process i.e. job(s) that were run in each client.
Does such an automic "upgrade check job" exist somewhere on the download site or elsewhere for upgrading from 11.2.1 HF2 to a later version?
You can use theRelease Notes(formerly know as the 'Upgrade Checker') for this.
Just select the components, the version you're running on and the one you want to upgrade to and start a search. It will provide you with the list of new features and bug fixes that were implemented between these 2 versions.
Here is a quick - truncated - example: