Envato have now completed the updates to their licensing:
We are pleased to confirm that we have made changes to the Regular License terms for items in the Blogging category in Themeforest.
The changes mean that items within this category, which includes Ghost themes, may be used for monetized membership websites under a Regular License.
The licensing clarification can be viewed here and here, part of our License FAQ page which legally forms part of the license. We have also updated our Help Centre article here.
We trust that this provides the clarity and certainty for your customers and community to operate using the Regular license, and appreciate this has taken longer than expected
Kind Regards,
Rohan Chandler
Envato - Author Management Director