I wanted to give you advance warning of an upcoming change related to the “Use as another user” feature. This is the feature that lets administrators assume the identity of other users.
With the change, we’ll be adding controls to prevent certain accounts from being the target of this feature. By default, this restriction will apply to all Admin users .
You will be able to choose which users to exclude or include via a new checkbox (“Admins can perform actions as”) on on each user listed on the People page.
This update is due to go live around the second week of February.