Provisioning Users prior to implementing Atlassian Access

[Bentsion Berg]

If we first provision users directly in JSM, is it easy enough to implement Atlassian Access with Azure AD after? Or is it better to first start with Atlassian Access? I found a tangentially related post from 2019 but there are no answers: 

https://community.atlassian.com/t5/Atlassian-Access-questions/Atlassian-Access-Module-How-to-manage-Pre-Existing-Jira-accounts/qaq-p/1182089

Thanks,

Ben