As you mention they have stated they are designing their own for multiple platforms, but at the moment they are using Qualcomm processors for their ARM offering

As you mention they have stated they are designing their own for multiple platforms, but at the moment they are using Qualcomm processors for their ARM offerings [https://www.lightreading.com/enterprise-cloud/infrastructure-and-platform/microsoft-qualcomm-bring-arm-to-azure/d/d-id/730959#:~:text=It's%20been%20rumored%20for%20years,its%20Azure%20cloud%20computing%20platform https://www.lightreading.com/enterprise-cloud/infrastructure....]