Jira products Maximum*Confluence Maximum*Overall Maximum*
I don't believe storage limits will change as of today.
On the same note, the storage page you linked has a last update as of 19JUL2018 and Atlassian does a very good job at ensuring their documentation stays updated.
I would suggest for now, vote for this feature request to get more storage:
We know that great teams require amazing project management chops. It's no surprise that great teams who use Jira have strong project managers, effective workflows, and secrets that bring planning ...