Technically this was possible before this.
Since the email to each slack user is an @company.com address all you need to do is take control of the employees email address, reset the slack password and login as the target user.
Since the email to each slack user is an @company.com address all you need to do is take control of the employees email address, reset the slack password and login as the target user.
Not necessarily
Very rare and unprofessional to allow someone's personal email access