ExternalAuth in 4.4.0rc2

I’ve been looking at an upgrade of pre 4.x system and noticed that
ExternalAuthId and been dropped from Users in 4.3, but is still
referenced in the now embedded Auth::ExternalAuth plugin man pages.
The ExternalAuthId column had been used to bridge LDAP to the user
accounts when users did not have an email address and had to use
another attribute/field from LDAP. Is it possible to keep the
ExternalAuthId column in 4.4, and future releases, or is there harm in
adding the field back to the users table and using LoadByCol?

Thomas Swan