To begin with, lets have a look at the functions of vSphere HA and SRM
vSphere HA: If any of the ESXi hosts in the cluster is inaccessible, vSphere HA will register and restart VMs on a health host in same vCenter server.
SRM: This is a disaster recovery solution, which enables recovery of VMs between 2 vCenter servers. For ex: If Site A is completely down, you can recover protected VMs at recovery site vCenter server.
There is no harm having placeholder VMs on a HA failover host at recovery site
As far as placeholder VMs are concerned, we can only provide a dedicated datastore where they can be stored. When we protect a VM in vCenter at Site A, a placeholder is created at vCenter at Site B.
These are not actual VMs(No disks, network, etc.) , but just inventory mappings which gets converted to an actual VM when a recovery is performed
Thanks for the response. As I thought the only risk is that during an SRM site failover then no HA host is available and vice versa.