Thank you for posting in Microsoft Q&A forum.
NAA is used when the computers can't use their local computer account to access content on distribution points.
If we have configured the site for HTTPS or Enhanced HTTP, a workgroup or Azure AD-joined client can securely access content from distribution points without the need for a network access account. Enhanced HTTP requires the distribution point to be running Windows Server 2012 or later when we do not use NAA.
So, according to your description, you can remove the NAA account.
If the answer is the right solution, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.