Hi,
I am not a Microsoft employee, but the general strategy is that over time Update Management Center replaces Azure Update Management. You can think of Update Management Center like v2 of Azure Update Management. Currently Update Management Center does not offer all the functionality available in Azure Update Management but the goal is Update Management Center to be fully on par of what Azure Update Management can do. The main purpose of building Update Management Center was to get rid of the dependencies of Azure Automation account and Log Analytics workspace and to be more native to Azure. Yes, using Azure Update Management requires using Log Analytics agent and the functionality will not be made available in Azure Monitor agent. Log Analytics agent is set to be deprecated but there are a couple of years before that happens. Log Analytics Agent and Azure Monitor agent can be used side by side. This means that if you use certain features of Azure Update Management that are not available in Update Management Center you can continue using Azure Update Management with Log Analytics agent even if you have also Azure Monitor agent installed for other Log Analytics/Sentinel functionalities. In general you can take two paths - wait until Update Management Center is on par of Azure Update Management and Azure Monitor agent is on par with Log Analytics agent and migrate after that or do side by side migration where you migrate over time parts of Azure Update Management, Azure Automation, Log Analytics and Sentinel when they become available in Azure Monitor agent and Update Management Center.
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