Is "Connected workspaces" implemented yet? Can freelancers/agencies edit with a colab seat?

The documentation here suggest that external agencies and freelancers will be able to edit inhouse files as long as they have their own Figma licenses, removing the need for us to pay for full edit licenses inhouse for them to use. 

It’s really unclear if this has been implemented or not with the latest changes on 11th March. If I downgrade our agency users seats to colab seats inhouse, can they still edit if they have their own full seats on their accounts?