I may be misunderstanding dataflow, and I will test this tomorrow, but here is my understanding of how it would work.
Backup Job: FAS8040(Production site ) -->SnapMirror -->FAS2554(DR Site) --->Veeam pulls data back from DR disk ---> E5660 (Veeam target at production site)
Now the Replication job runs, with backup set as source. E5660 (Veeam target storage for backups) ----->FAS2554 (DR Site)
Unless I'm missing something here, there is no way in our scenario (production and backup storage at one location, DR storage at another site) to allow NetApp snapmirror and snapvault to do the data moving.
We would want this flow, with Veeam triggering the snapvault:
Replication Job: FAS8040 (production site) ---snapmirror/snapvault----> FAS2554 ---> Veeam then registers the replicated VM's in the DR cluster.
Maybe a feature request?