I want to deprecate getUserCaseDBKey() in core, and CentralAuth's GlobalGroupPermissions is one of the places it's used. I propose that the internal identifier for all global groups must be lowercase so we don't have to deal with casing at all.
Out of the global groups on Wikimedia sites, only https://meta.wikimedia.org/wiki/Special:GlobalGroupPermissions/OTRS-member is not all lowercase already. I'll ask for that to be renamed.