It's a very good question.
According to netapp interoperability tool: It says supported for-
SC 4.1.1 & 4.2 with VMwar vCenter 6.7 Update 2
However, the tool does not distinguish between standalone or HA (Be it SQl,Exch,Oracle,MSCS) it simply mentions the application name. But if you read their documnetation for 'Clustered' applications, they mention - You should install plug-ins on the all the nodes of the cluster. I guess that should apply to vCenter HA as well.
http://docs.netapp.com/ocsc-41/index.jsp?topic=%2Fcom.netapp.doc.ocsc-isg%2FGUID-8674BCB1-0CA6-4B2B-8D07-146E1AB9AE79.html
Extract from documentation above: If you install plug-ins on a cluster (WSFC, Oracle RAC, SQL Always On Availability Groups, or Exchange DAG), they are installed on all of the nodes of the cluster.
I guess NetApp might need to include vCenter HA into their documentation ?
I think someone from NetApp could shed some more light on this.
Thanks,
-Ashwin