While in general users already have this right it is granted both as security in case that changes for some reason and because one of the core purposes of the group is to create accounts for new WMF staff members.
Allows users to lock or unlock global account.
This allows the staff member to lock WMF accounts when they are no longer with staff. It will also allow them to unlock both to fix mistakes or for staff who are returning after previously being a member of staff.
Allows users to not be subject to account/IP based rate limits.
This is mostly to allow the staff member to create multiple accounts without hitting the rate limit if, for some reason or another, a large number are required to be created on one day or if they are using the API to create them relatively quickly.
Allows users to override the title or username blacklist.
The pattern "WMF" is blocked from being created by regular users. This will allow the staff member to create work accounts with the required WMF tag.