Change AppleID to a new email address
My girlfriend has changed her email provider and therefore she has to change her Apple ID to the new (icloud.com) email address. Up until a few days ago, this web page included a section that said it is first necessary to logout of iCloud on all devices (like iPhone, iPad, macbook, apple tv), which made sense to me, but now this section has been removed.
Is it really no longer necessary? What happens to all those devices which are currently logged in?
In the german language version of this web page, this section is still there. Confusing!!