Starting on June 15th, 2017 Microsoft Azure has increased the maximum size limit of the virtual hard disks(VHDX) for IaaS VMs, and as a consequence they now allow to perform the export of the VHDX of up to 4TB. The Core should also support such configuration.
To provide flexibility for customers to provision an appropriate disk size which matches their workloads, we introduce two new disk sizes in P40 (2TB) and P50 (4TB) for both Managed and unmanaged Premium Disks; S40 (2TB) and S50 (4TB) for Standard Managed Disks. Customers can also provision the maximum disk size of 4,095 GB for Standard unmanaged disks.
For more details, please review Microsoft's article Announcing large disk sizes of up to 4 TB for Azure IaaS VMs.