Normally on application upgrade we forcibly reload compatibility information from install.rdf for any add-ons in the application directory however currently if the database has changed schema we use migrated values from the old database instead.

Per policy at https://wiki.mozilla.org/Bug_Triage/Projects/Bug_Handling/Bug_Husbandry#Inactive_Bugs. If this bug is not an enhancement request or a bug not present in a supported release of Firefox, then it may be reopened.