Today I had to face this issue of expired Domain Administrator password in a DC hosted in Azure IaaS. This is my SCCM lab environment which has a single DC and completely resides in Azure. The worst thing happened to me was, expired passwords of;
1. Local Admin account which I created at the time of creating the DC VM and also the Domain Admin.
2. Other only Domain Admin account.
3. SCCM Administrator account.
at the same time.