Complete list is available on above link for the deprecated features in AX7 but the important one to me as Technical on AX is AIF service. here is statement from Microsoft about it. I will share separate blogs about the replacements and defiantly in AX7 we have better options for implementing the integrations.
In Application Integration Framework (AIF), data can be exchanged with external systems through business logic that is exposed as services. Microsoft Dynamics AX includes services that are based on documents and .NET Business Connector (AxBC). A document is created by using XML. The XML includes header information that is added to create a message that can be transferred into or out of Microsoft Dynamics AX. Examples of documents include sales orders and purchase orders. However, almost any entity, such as a customer, can be represented by a document. Services that are based on documents use the Axd <Document> classes.
|Reason for deprecation||The architecture of AIF and AxDs could not be scaled to a cloud service. There were performance issues around bulk import.|
|Replaced by another feature?||In the current version of Dynamics AX, this feature is replaced by Data Import/Export framework, which supports recurring bulk import/export. For AxBC, we recommend that you use the actual tables.|
|Modules affected||AxDs, AxBCs, and AIF|