As pointed by Christopher, The idea is to start using sensitivity lables from the Compliance & Security Center. This sensitivity labels are just AIP labels....if you are using AIP labels and you want move to the "unified" labels, you will have to migrate your AIP labels
To be precise, AIP labels and sensitivity labels share the same common foundation of Azure rights management. You can certainly use both to protect information inside Office 365, but given that sensitivity labels are now available to all E3 and E5 tenants, I would go with them and avoid the need to pay for AIP licenses. You still need AIP if you want to protect information outside Office 365. See https://office365itpros.com/2018/11/27/office-365-sensitivity-labels-protection/ for more information.