Premium A+ Content is available to brand-registered sellers, but it's not immediate access just from being brand registered. There are specific eligibility requirements you'll need to meet first:

• You have already published A+ Brand Story to all ASINs that you own within your catalog. Essentially, all ASINs within your A+ Content Manager need to have a published Brand Story. You can confirm this by accessing the A+ Content Manager and searching to see if you have created and published a project. You will also see A+ Brand Story on your ASINs under the “From the Brand” fields on the detail page.
• You have had at least 5 project submissions of A+ Content that have been approved and published within the past 12 months. You can confirm this by accessing the A+ Content Manager and checking the status of your submitted projects and the last published date. This is to ensure our guidelines are being adhered to.

TLDR: yes, you will still need those 5 approved Basic A+ content submissions. That requirement has not been removed.

Once you meet all three criteria, you don't need to apply or contact anyone. You'll see a banner notification confirming your access.