Hi
It's true, if the free E1 subscription is showing on the list of subscription options it means you have been verified.
Now you are eligible for Office 365 for Education E1 licences (which are free), but you still need to go through a purchase procedure with Microsoft when you wish to add additional licences:
Staff licences = Office 365 Education E1 for Faculty.
Student licences = Office 365 Education E1 for Students.
Procedure
1. Log on to the Office 365 Admin center with your Office 365 Global Administrator account username/password.
2. On the left-hand side of the screen, select 'purchase services'.
3. A list of available Education Plans should be displayed.
4. Locate the required licence (for the E1 licences you will see they have a $0.00 value).
5. Click the 'Add more' link.
6. A 'How many licenses do you want to add' screen will be displayed.
7. In the 'Add more' box, enter the number of additional licences you'd like to purchase (remember these are free).
8. Click the 'add licenses' button.
9. A 'Review the details of your order' screen will be displayed.
10.Click 'place order'.
11. An 'Order confirmation' screen will be displayed.
12. Click the Finish button.
Yeah it will remain free for educational institutions in the future. Although, you also may contact the local sales and billing support
support.office.com/.../Contact-Office-365-for-business-support-32a17ca7-6fa0-4870-8a8d-e25ba4ccfd4b
BR,