No. Existing users of SFC2014 must explicitly request access to SFC2021 by providing their Unique identifier at the Commission (uid) to their MS Liaison.
This Unique identifier at the Commission (uid) is the same one that is used for the SFC2014 account and can be found accessing https://webgate.ec.europa.eu/cas and logging into EU Login and clicking on the gear at the top right corner to display the menu and select 'My Account' -> 'My EU Login Account Details' -> 'Unique identifier at the Commission (uid)'
Alternatively if a user already has an SFC2014 account they can login to SFC2014 and find their Unique identifier at the Commission (uid) on the top-left of the screen:
Once the access request sent by the MSL is processed users will then be able to access SFC2014 and SFC2021 with the same Username and Password.