Azure Xen disks

[Gro Goto]

Hi all, 

I have an environment in Azure with a lot of Xen virtual machines (VMs). I want to convert disks of these VMs from unmanaged to managed. I want to do this because the cost of unmanaged disks is huge to compare with managed, As I got it, I can't do this because of

Quote

This version of XenApp and XenDesktop only supports an Azure unmanaged disk storage system. By default, Azure uses a managed disk storage system. For information about managed and unmanaged Azure storage solutions, refer to Azure managed disks.

https://docs.citrix.com/en-us/xenapp-and-xendesktop/7-15-ltsr/install-configure/install-prepare/azure-resource-manager.html

I want to know: is this up to date information? What will happen if I'll try to convert disks? 

Any tips for the disks cost reduction without disks convertation?